Which Tax Tables to use?

[junk.jason]

Hi,

I am new to excel and I took my whole Sunday searching high and low
for a formula or template (yea I guess I am lazy, but don't want to
spend my whole Sunday doing something heh, especially reinventing the
wheel) to calculate Federal withholding to organize my personal budget
and figure what-if scenarios. I finally wrote/copied code that I found
bits and pieces of. I learned a lot about tax tables and such. However,
it has come to my attention that there are at least (2) official
sources for Federal Tax tables. The trouble is, both are different and
I am not sure which one to use.

The first source is "Publication 15", aka "Circular E, Employer's Tax
Guide".
http://www.irs.gov/pub/irs-pdf/p15.pdf

The second is the "Wage Bracket Method Table for Computing Income Tax
Withholding From Gross Wages"
http://www.irs.gov/publications/p15a/21453t29.html

I made a replica (just the first part done so far that pertains to me)
of the Wage Bracket Method Table on a worksheet and am referencing the
formula's there. I will likely change the actual positions of the cell
references later, as I want it to look as close to the actual table as
possible. I figure that when I share this workbook I am creating, I
would like to have as reference things that look familiar and also
inform users how things are being calculated. I was going to learn how
to use an array, but I wasn't sure how to do that since I have a column
with the word subtract (per the Wage Table document). I will likely
make a work-around later.

So, here is my formula:
=IF(AND(A1>B8,A1<=C8),((A1-E8)*F8),IF(AND(A1>B9,A1<C9),((A1-E9)*F9),IF(AND(A1>B10,A1<C10),((A1-E10)*F10),IF(AND(A1>B11,A1<C11),((A1-E11)*F11),IF(AND(A1>B12,A1<C12),((A1-E12)*F12),)))))


I hope it makes since.. and also, here is an image on fileshack of
what my table looks like, that should help.

http://img100.imageshack.us/my.php?image=taxtable8iu.png

I used the cell references in the hope that next year I can just use
the table again, with it updated. I plan to distribute a workbook that
allows you to enter in your pertanant information, such as dependants,
married, etc and it update/change the formula's required to calculate
the actual withholding. In the workbook will be a worksheet to
calculate monthly budget, all unlocked so that a user can alter,
protect as they wish.

Thank you for your help in advance!

-Alden

 

[joeu2004]

it has come to my attention that there are at least (2) official
sources for Federal Tax tables. The trouble is, both are different and
I am not sure which one to use.

The first source is "Publication 15", aka "Circular E, Employer's Tax
Guide". http://www.irs.gov/pub/irs-pdf/p15.pdf

The second is the "Wage Bracket Method Table for Computing Income Tax
Withholding From Gross Wages"
http://www.irs.gov/publications/p15a/21453t29.html

As the URL path name suggests, the second table comes from IRS Pub
15-A. As that Pub and Pub 15 explain, there are a variety of methods
that employers can use to compute withholding, depending on the payroll
system (if any) that they use. Consequently, your ability to match
exactly the amount of tax that an employer might withhold depends on
knowing exactly the method of calculation used by that employer. That
is usually unnecessary. If you compare all of the methods, hopefully
the difference is no more than $50 per pay period.

For planning purposes, I simply use the Percentage Method in IRS Pub
15. I think it is the easiest to set up in Excel. For example, the
taxable income for a semimonthly salary is:

=GrossIncome - Allowances*137.50

The income tax for Married to withhold semimonthly is:

=10%*max(0,TaxableInc-333) + 5%*max(0,TaxableInc-954) + 10%*max(0,
TaxableInc-2835)
+ 3%*max(0, TaxableInc-5288) + 5%*max(0,TaxableInc-8144) + 3%*max(0,
TaxableInc-14315)

For planning purposes, don't forget to account for Soc Sec and Medicare
withholding (FICA).

Also, if a significant portion of compensation is in bonuses, be sure
to study the Supplement Wages section of Pub 15 and decide how to apply
the employer's choices.

Finally, if you work in a state that has income taxes and disability
insurance tax (e.g. California), be sure to study the information in
similar "pubs" for that state.

 

[JLatham]

It sounds to me like joeu2004 knows a whole lot more about this than I do,
but I agree that you want to be looking at Publication 15, and that the
percentage method is easier to set up in Excel. Also, it is independent of
information on the W4.

I started working with someone elsewhere in setting up an Excel workbook to
help do payroll - ended up abandoning the project because of my ignorance of
all the very complex rules for it all. But I did make progress in
calculating the withholding part of it using the percentage method. You can
see the work I did do in this workbook:
http://www.jlathamsite.com/uploads/A_StartAt_DoingPayroll.xls
perhaps it'll give you some ideas. Then again, may confuse you all to heck
- I know it did me before it was open. It gets nasty because there are so
many conditions to check for and different tables to use. It would get a lot
cleaner if you are just trying to do it all for one person with known set of
'conditions'.

 

[joeu2004]

I agree [...] that the percentage method is easier to set up in Excel.
Also, it is independent of information on the W4.

I am not sure what you intended to say, but the number of allowances
comes directly from the W4 that you file with your employer. (And the
DE4 for California.) In that sense, the withholding computation
(however you choose to do it) is __not__ independent of the W4.

PS: In my original response, I neglected to include a W4 option that
many employers support, namely the ability to withhold an additional
fix amount per pay period in addition to the amount determined by the
withholding computation. Yet another reason why income tax withholding
is "dependent" on the W4.

 

[junk.jason]

Thank you both for your responses. The thing is, I used the tax table
and my formula, and with a $368.20 "test", it came within 2 cents. I
think I can live with that. I started with the excel template "Personal
Monthly Budget" from office.microsoft.com . It has an actual and a
projected monthly income. I plan to take that worksheet (heavily
modified) and eventually be able on it to put in (or on another sheet)
my pay rate and hours, my overtime/bonus pay, subtract allowances and
insureance, etc.and have the worksheets automatically figure out my
gross wages.

I want it to figure out my federal, state, and social security
withholding, tax out my tihes, everything. All that bascially
completly varible with a person's pertenant information giving you a
complete overview. I know it will be a BIG project, especially for
someone who is relatively new to Excel and whose only experiance with
programming anything is Counter Strike Scripts, lol. I guess I will
have to take into account different emplorer methods of withholding,
but most should be very similar and I could always leave it open to
adjustment by the individual using the workbook.


I just got in from work after being at Walmart for two hours with bad
shoes and $160 in groceries. So I am none the less tired and will check
out your sample workbook in the morning. I can't wait.

I agree [...] that the percentage method is easier to set up in Excel.
Also, it is independent of information on the W4.

I am not sure what you intended to say, but the number of allowances
comes directly from the W4 that you file with your employer. (And the
DE4 for California.) In that sense, the withholding computation
(however you choose to do it) is __not__ independent of the W4.

PS: In my original response, I neglected to include a W4 option that
many employers support, namely the ability to withhold an additional
fix amount per pay period in addition to the amount determined by the
withholding computation. Yet another reason why income tax withholding
is "dependent" on the W4.

 

[joeu2004]

Thank you both for your responses. The thing is, I used the tax table
and my formula, and with a $368.20 "test", it came within 2 cents.

I like to play the same game.

But as I said before, the accuracy of any computation will depend on
your ability to match your employer's method. If you employer uses the
same tax tables, then yes, your results should be accurate.

And your formula is unnecessarily complex. If you insist on sticking
with the tax tables, you should learn how to use the lookup functions
-- lookup(), vlookup() and hlookup().

eventually be able on it to put in (or on another sheet)
my pay rate and hours, my overtime/bonus pay, subtract allowances and
insureance, etc.and have the worksheets automatically figure out my
gross wages.

I think you mean net wages or take-home pay, not gross wages. Your
gross wages -- your pay before any withholding and pretax deductions --
are input to any computation, not something to be computed.

You might also want to keep in mind that withheld tax is not
necessarily the same as your tax liability. If you are careful, they
can be very close. But often, they are not. You need to be aware of
any shortfall in income tax withholding and budget additional savings
to cover taxes owed when you file your return next year.

 

[junk.jason]

Yea I am tired, I tried to get what i was saying straight but I figured
you would understand. I figured I would end up using those functions as
it would make it easier, but at least I figured out what I was doing
enough to come up with a formula half on my own.

I do understand that withholding is not the same as liability. For
right now, I kind of like having the "regular" amount taken out and
getting something back. Eventually I will change that I am certain. For
now, I am just lookin to "accurately" calculate it. I know I can easily
do what I want to do, since specifically just for me, and make it easy
to update at anytime. In the future I will add things so that others
can change values with a few toggles and have the sheets make the major
changes automatically.

I guess I shoul have read "Publication 15" instead of just looking for
the tables. But it was late and I got a working formula so I was happy.
Like I said I spent way to much time on that. But now I can do it
agian. So it was worth it.

The percentage method bothered me as I feared it may be more of an
"estimate" than the tables, but I guess it all just depends. I wonder
what the real differance is.

When you said you liked to play the same game, I thought at first that
you liked figuring out taxes and had done some formulas which go tme
excited, heh. So, where are you at? Play in some low pinging servers? I
have been playing Source if I get to play usually. Got a newer rig,
might as well justify it somehow.

Again, thank you for your time.

 

[Marcelo]

what are you looking for?



"unknown" escreveu:

 

[joeu2004]

Errata....

it has come to my attention that there are at least (2) official
sources for Federal Tax tables. The trouble is, both are different and
I am not sure which one to use.

The first source is "Publication 15", aka "Circular E, Employer's Tax
Guide". http://www.irs.gov/pub/irs-pdf/p15.pdf

The second is the "Wage Bracket Method Table for Computing Income Tax
Withholding From Gross Wages" http://www.irs.gov/publications/p15a/21453t29.html

Depending on what you looked at in Pub 15, the two tables are
mathematically identical. I was fooled by the title that you used, and
I was not careful when I double-checked. Pub 15 uses the term
"Percentage Method" versus "Wage Bracket" to distinguish between an
algorithmic method versus a table lookup. So I ass-u-me-d you were
looking at the "Wage Bracket" tables in Pub 15. But now I realize that
the Pub 15-A table that you point to is really entitled "Wage Bracket
Percentage Method", something of an oxymoron in IRS parlance. I guess
the distinction that the IRS is trying to make is: "based on gross
income" (wage bracket) versus "based on taxable income" (arguably
"taxable income bracket").

In any case, if you compare the computation for the Wage Bracket
Percentage Method (second reference) to the computation for the
Percentage Method in the first reference, you will see that they are
identical after you "rearrange terms", an algebraic methodology.
Consider the 15% bracket (taxable income of $192.01 to $620) for Single
Weekly, the table that you excerpted in your spreadsheet. For the
second reference, the computation is:

(Gross - 63.46*Allowances - 98) * 15%

For the Percentage Method in the first reference, the computation is:

(Gross - 63.46*Allowances - 192)*15% + 14.10
= (Gross - 63.46*Allowances - 192 + 14.10/15%) * 15%
= (Gross - 63.46*Allowances - 192 + 94) * 15%
= (Gross - 63.46*Allowances - 98) * 15%

Note that Gross - 63.46*Allowances is "taxable income".

So, here is my formula:
=IF(AND(A1>B8,A1<=C8),((A1-E8)*F8),IF(AND(A1>B9,A1<C9),((A1-E9)*F9),IF(AND(A1>B10,A1<C10),((A1-E10)*F10),IF(AND(A1>B11,A1<C11),((A1-E11)
*F11),IF(AND(A1>B12,A1<C12),((A1-E12)*F12),)))))

I believe the following should work just as well for Single Weekly.
Assuming that A1 is Gross Wages and B1 is Allowances:

=max(0, 10%*(A1 - B1*63.46 - 51), 15%*(A1 - B1*63.46 - 98), 25%*(A1 -
B1*63.46 - 306.80), 28%*(A1 - B1*63.46 - 424.89), 33%*(A1 - B1*63.46 -
817.03), 35%*(A1 - B1*63.46 - 1142.23))

Of course, you can save yourself some typing by replacing A1 - B1*63.46
with C1 (taxable income) computed as:

=A1 - B1*63.46

You might need to convince yourself that the single max(...) formula
above works for all combinations of allowances, given that the second
reference shows different gross-wage cut-offs and offsets for each tax
bracket. For example, for 15%, the gross wage range is $192.01 to $620
for zero allowances, but $255.47 to $683.46 for one allowance. But
also note that the offsets are -98 and -161.46 respectively. If we
call the zero-allowance gross wage limits the "taxable income" (T),
then algebraically the one-allowance case for the 15% bracket becomes:

Gross - 161.46
= (T + 63.46) - (98 + 63.46)
= T + 63.46 - 98 - 63.46
= T - 98

As you can see, the additional factor (Allowances*63.46) for the
cut-offs and offset simply cancels out.

If the "higher mathematics" confuses you, I suggest that you simply
compare the results of all 3 formulations -- yours, my replacement for
yours (above) and my marginal rate formula (previous posting). You
should get the same results for the same gross income and number of
allowances. (Note: There might a difference of a penny or so due to
round-off anomalies.)

Which formulation that you use is a matter of taste. But consider
this: the Percentage Method (aka marginal rate) tables are used
consistently in IRS Pubs and Forms, whereas the other tables are not
always spelled out. Also, if your state has an income tax, it will
undoubtedly show marginal rate tables, but it may or may not have "wage
bracket" tables. Ergo, I think it behooves you to become familiar with
the marginal rate formulation that I described in my first posting.

But to each his own. The main purpose of this posting is to correct
any misleading impression that my first posting might have left.

If you compare all of the methods, hopefully
the difference is no more than $50 per pay period.

I am sure that is wrong. I was thinking of something unrelated.
First, again, I was thinking of the difference between the Percentage
Method and the Wage Bracket Method in Pub 15 parlance. Second, the
difference should m-u-c-h smaller -- probably within $1 due to
round-off. For example, for Single Weekly with zero allowances and
gross wages of $620, the withholding based on the Wage Bracket table is
$78, whereas is it $78.30 based on the Percentage Method table.

 

[junk.jason]

Sorry I haven't respnded before now. I have been tired and "taxed" out
myself. I believe that the formula you have from the post above is what
I am looking for. As you can see, my formula is limited, missing the
highest bracket because of the 7 nested rule. I knew there had to be a
much better and fully functional way.

Depending on what you looked at in Pub 15, the two tables are
mathematically identical. I was fooled by the title that you used, and
I was not careful when I double-checked. Pub 15 uses the term
"Percentage Method" versus "Wage Bracket" to distinguish between an
algorithmic method versus a table lookup. So I ass-u-me-d you were
looking at the "Wage Bracket" tables in Pub 15. But now I realize that
the Pub 15-A table that you point to is really entitled "Wage Bracket
Percentage Method", something of an oxymoron in IRS parlance. I guess
the distinction that the IRS is trying to make is: "based on gross
income" (wage bracket) versus "based on taxable income" (arguably
"taxable income bracket").

So I take it the tables will give me the same answer, just a different
path of reaching the same point. I can understand that. I noticed
myself that the table was labled the "Wage Bracket Percentage Method"
and knew you hadn't "run the numbers" to see what I had actually used
and done. That is okay, as you didn't need to to see what I was going
for. You have helped me a lot, and I am sure that just looking at your
formula will allow me to understand a lot in how to use the "=max"
function in my own formulas. I am to tired to attempt to comprehend it
all fully tonight. But rest assured once I make some time for me (get
that MY time is spent figuring taxes lol) I will hard at work putting
what you have done for me to good use.

Hope you enjoyed your holiday!

 

[Jason.Alden.Benoit]

I believe the following should work just as well for Single Weekly.
Assuming that A1 is Gross Wages and B1 is Allowances:

=max(0, 10%*(A1 - B1*63.46 - 51), 15%*(A1 - B1*63.46 - 98), 25%*(A1 -
B1*63.46 - 306.80), 28%*(A1 - B1*63.46 - 424.89), 33%*(A1 - B1*63.46 -
817.03), 35%*(A1 - B1*63.46 - 1142.23))

Of course, you can save yourself some typing by replacing A1 - B1*63.46
with C1 (taxable income) computed as:

=A1 - B1*63.46

You might need to convince yourself that the single max(...) formula
above works for all combinations of allowances, given that the second
reference shows different gross-wage cut-offs and offsets for each tax
bracket. For example, for 15%, the gross wage range is $192.01 to $620
for zero allowances, but $255.47 to $683.46 for one allowance. But
also note that the offsets are -98 and -161.46 respectively. If we
call the zero-allowance gross wage limits the "taxable income" (T),
then algebraically the one-allowance case for the 15% bracket becomes:

Gross - 161.46
= (T + 63.46) - (98 + 63.46)
= T + 63.46 - 98 - 63.46
= T - 98

As you can see, the additional factor (Allowances*63.46) for the
cut-offs and offset simply cancels out.

Yes, that made it simple to understand. It has been awhile since I
have done Algebra. I need to obviously brush up before I go back to
school this spring.

I figured out my GA state taxes by hand and I could come within a few
pennies if I used the federal taxable wages, and I was over if I used
just my gross pay.

For example on one check I had $ 388.80, with 370.30 taxable
federally.

So I worked out:

370.30 - 44.25 = 326.05
326.05 - 135 = 191.05
191.05 * 6% = 11.463 + 4.42 = 15.883

from this publication.

http://www.etax.dor.ga.gov/taxguide/emplr_TaxGuide2005.pdf

I am single with no (zero) allowances.

I have been working on trying to go about making a formula for this
work but I guess I will have to keep at it. I need to find a few hours
without getting interrupted I guess.

If you however, can figure a formula without taking to much of your
time, it would greatly be appreciated. I know if you made one it would
undoubtedly be far simpler than my own.

Should I get one working I will get back to you.

 

[joeu2004]

I figured out my GA state taxes by hand
[....]
from this publication.
http://www.etax.dor.ga.gov/taxguide/emplr_TaxGuide2005.pdf

I am single with no (zero) allowances.

And inferentially, it appears that you are paid weekly.

I figured out my GA state taxes by hand and I could come within a few
pennies if I used the federal taxable wages, and I was over if I used
just my gross pay.
For example on one check I had $ 388.80, with 370.30 taxable
federally.

Let me clarify and correct the terminology in my first response in this
thread.

What I called "gross income" should be called "taxable gross pay (or
compensation)".
I am guessing that $370.30 is your federal "taxable gross" pay. That
is your gross pay less qualified federal pretax deductions, e.g.
employee contributions to a 401(k) or other employer pension plan and
to pretax accounts such as medical and commuter benefits. In theory,
your state's "taxable gross" pay may or may not be the same as the
federal taxable gross pay. That is the state's choice to make.
Apparently for GA, it is the same, based on your observation and based
on page 18 of the cited GA document ("Are contributions to qualified
.... plans taxable?"). I believe that is usually the case.

What I call "taxable income" is also called "wages subject to
withholding". Compare the definition of "taxable income" on page 8
with the example on page 40 of the cited GA document.

If you however, can figure a formula without taking to much of your
time, it would greatly be appreciated.

Not a problem. However, the GA instructions are poor and unclear on a
few points. The following is my interpretation. Use at your own risk.

I assume that you are looking at pages 41-43 of the cited GA document.
The GA Percentage Method is similar to the Federal Percentage Method.
You could use the formulation in my first response as a paradigm. By
the way, if you do not understand that formulation and you want an
explanation of the limits and the percentages in the formula, let me
know.

Looking at Form G-4, GA's equivalent to the Federal W-4, you declare
personal allowances (0-1 for single; 0-2 for others), dependent
allowances and additional allowances. I lump the latter two together
as "other allowances".

Thus, the gaTaxableIncome for Single Weekly can be computed by:

=gaTaxableGross - 44.25 - PersonalAllowances*51.92 -
OtherAllowances*57.50

Ostensibly, the gaWithholding might be computed by:

=1%*gaTaxableIncome + 1%*max(0,gaTaxableIncome-14.50) +
1%*max(0,gaTaxableIncome-43.50) + 1%*max(0,gaTaxableIncome-72) +
1%*max(0,gaTaxableIncome-101) + 1%*max(0,gaTaxableIncome-135)

I put that in a general form that works for all marginal tax tables.
But you might notice that 1% is a common factor in GA's case. So the
above can be simplified as follows:

=1%*(gaTaxableIncome + max(0,gaTaxableIncome-14.50) +
max(0,gaTaxableIncome-43.50) + max(0,gaTaxableIncome-72) +
max(0,gaTaxableIncome-101) + max(0,gaTaxableIncome-135))

However, that computes a tax of $15.90, whereas you correctly manually
compute $15.88. The answer lies in some anomalies of the GA table.
Consider the top taxable income of the 5% bracket, $135. The
withholding amount is (135-101)*5% + 2.74 = 1.70 + 2.74 = $4.44. That
should also be the amount to add in the 6% for taxable incomes over
$135. But GA adds $4.42 instead. There are other similar anomalies in
the Single Weekly table.

The following formula computes exactly the same withholding amount as
the Single Weekly table in the cited GA document.

=max(0, 1%*gaTaxableIncome, 2%*(gaTaxableIncome-14.50)+0.14,
3%*(gaTaxableIncome-43.50)+0.72, 4%*(gaTaxableIncome-72)+1.59,
5%*(gaTaxableIncome-101)+2.74, 6%*(gaTaxableIncome-135)+4.42)

Alternatively, combining constants:

=max(0, 1%*gaTaxableIncome, 2%*gaTaxableIncome-0.15,
3%*gaTaxableIncome-0.585, 4%*gaTaxableIncome-1.29,
5%*gaTaxableIncome-2.31, 6%*gaTaxableIncome-3.68)

It had never occurred to me that marginal rate tables might have such
anomalies. I might switch to this latter paradigm myself. (I have
been using my other formula for a very long time!)

On the other hand, you said that your figure ($15.88) differed by "a
few pennies" from your employer's figure. If the employer computed
$15.90, perhaps he is using a formula similar to my first one.

 

[Jason.Alden.Benoit]

I am going to a company picnic in a few and when I get back I will look
over this more. Looks like good stuff, thank you.

However something seems to be wrong. I worked out I believe $15.88 for
gaTaxable income. My check states $15.91. Using your formula however I
get $18.558. (18.56) Perhaps I am doing something wrong? I just renamed
the cell I was using for federal gross income to gaTaxableincome.

I am glad that the publication wasn't clear to you either. I was
hoping it wasn't just me. Also, I apoligize for giving insufficient
information, good thing you are intuitive!

I figured out my GA state taxes by hand
[....]
from this publication.
http://www.etax.dor.ga.gov/taxguide/emplr_TaxGuide2005.pdf

I am single with no (zero) allowances.

And inferentially, it appears that you are paid weekly.

I figured out my GA state taxes by hand and I could come within a few
pennies if I used the federal taxable wages, and I was over if I used
just my gross pay.
For example on one check I had $ 388.80, with 370.30 taxable
federally.

Let me clarify and correct the terminology in my first response in this
thread.

What I called "gross income" should be called "taxable gross pay (or
compensation)".
I am guessing that $370.30 is your federal "taxable gross" pay. That
is your gross pay less qualified federal pretax deductions, e.g.
employee contributions to a 401(k) or other employer pension plan and
to pretax accounts such as medical and commuter benefits. In theory,
your state's "taxable gross" pay may or may not be the same as the
federal taxable gross pay. That is the state's choice to make.
Apparently for GA, it is the same, based on your observation and based
on page 18 of the cited GA document ("Are contributions to qualified
... plans taxable?"). I believe that is usually the case.

What I call "taxable income" is also called "wages subject to
withholding". Compare the definition of "taxable income" on page 8
with the example on page 40 of the cited GA document.

If you however, can figure a formula without taking to much of your
time, it would greatly be appreciated.

Not a problem. However, the GA instructions are poor and unclear on a
few points. The following is my interpretation. Use at your own risk.

I assume that you are looking at pages 41-43 of the cited GA document.
The GA Percentage Method is similar to the Federal Percentage Method.
You could use the formulation in my first response as a paradigm. By
the way, if you do not understand that formulation and you want an
explanation of the limits and the percentages in the formula, let me
know.

Looking at Form G-4, GA's equivalent to the Federal W-4, you declare
personal allowances (0-1 for single; 0-2 for others), dependent
allowances and additional allowances. I lump the latter two together
as "other allowances".

Thus, the gaTaxableIncome for Single Weekly can be computed by:

=gaTaxableGross - 44.25 - PersonalAllowances*51.92 -
OtherAllowances*57.50

Ostensibly, the gaWithholding might be computed by:

=1%*gaTaxableIncome + 1%*max(0,gaTaxableIncome-14.50) +
1%*max(0,gaTaxableIncome-43.50) + 1%*max(0,gaTaxableIncome-72) +
1%*max(0,gaTaxableIncome-101) + 1%*max(0,gaTaxableIncome-135)

I put that in a general form that works for all marginal tax tables.
But you might notice that 1% is a common factor in GA's case. So the
above can be simplified as follows:

=1%*(gaTaxableIncome + max(0,gaTaxableIncome-14.50) +
max(0,gaTaxableIncome-43.50) + max(0,gaTaxableIncome-72) +
max(0,gaTaxableIncome-101) + max(0,gaTaxableIncome-135))

However, that computes a tax of $15.90, whereas you correctly manually
compute $15.88. The answer lies in some anomalies of the GA table.
Consider the top taxable income of the 5% bracket, $135. The
withholding amount is (135-101)*5% + 2.74 = 1.70 + 2.74 = $4.44. That
should also be the amount to add in the 6% for taxable incomes over
$135. But GA adds $4.42 instead. There are other similar anomalies in
the Single Weekly table.

The following formula computes exactly the same withholding amount as
the Single Weekly table in the cited GA document.

=max(0, 1%*gaTaxableIncome, 2%*(gaTaxableIncome-14.50)+0.14,
3%*(gaTaxableIncome-43.50)+0.72, 4%*(gaTaxableIncome-72)+1.59,
5%*(gaTaxableIncome-101)+2.74, 6%*(gaTaxableIncome-135)+4.42)

Alternatively, combining constants:

=max(0, 1%*gaTaxableIncome, 2%*gaTaxableIncome-0.15,
3%*gaTaxableIncome-0.585, 4%*gaTaxableIncome-1.29,
5%*gaTaxableIncome-2.31, 6%*gaTaxableIncome-3.68)

It had never occurred to me that marginal rate tables might have such
anomalies. I might switch to this latter paradigm myself. (I have
been using my other formula for a very long time!)

On the other hand, you said that your figure ($15.88) differed by "a
few pennies" from your employer's figure. If the employer computed
$15.90, perhaps he is using a formula similar to my first one.

 

[joeu2004]

However something seems to be wrong. I worked out I believe $15.88 for
gaTaxable income. My check states $15.91. Using your formula however I
get $18.558. (18.56) Perhaps I am doing something wrong? I just renamed
the cell I was using for federal gross income to gaTaxableincome.

That was your mistake. Your federal gross income is 370.30. The
gaTaxableIncome is 326.05 = 370.30 - 44.25, subtracting the standard
deduction for single weekly.

I am glad that the publication wasn't clear to you either. I was
hoping it wasn't just me.

I only quibble with a few points. I already mentioned one: the fact
that the amount added in one bracket is not always the same as the
amount computed for the top end of the previous bracket, even if we
allow for rounding differences. Some other quibbles (page numbers
refer to the GA document that you cited previously):

1. I am not sure I understand the intent or significance of Step 5 on
page 40, to wit: "If zero exemption is claimed, subtract the standard
deduction only". What does "zero exemption" mean? (Rhetorical.)
There is exemption from withholding; but in that case, there is no need
to subtract anything since there is no withholdoing to compute. There
is zero allowances ("exemption" is a common misnomer); but in that
case, Step 5 is just a simplification of Steps 1-3. My interpretation
is the latter.

2. Both Step 3 and Table E on page 40 refer to (only) "dependent
allowances", which GA Form G-4 (withholding certificate) distinguishes
from "additional allowances". Are we to ass-u-me that you exclude
"additional allowances" from the computation? (Rhetorical.) That
would defeat the purpose of declaring additional allowances. My
interpretation is that "dependent allowances" includes "additional
allowances" for this purpose. That interpretation is bolstered by the
footnote to the Example on page 40, to wit (emphasis added): "Skip
Step 2(b) if employee does not claim children or __additional__
allowances", where Step 2b is "Less Dependent Allowance".

3. In Tables F-H on pages 41-43, the low end of each bracket is labeled
"At Least" instead of "Over". If they really mean "At Least", that
would be ambiguous with the label of the high end of the previous
bracket, namely "But Not Over". For example, if taxable income for
Single Weekly is $135, should the withholding be $4.44 = 2.74 +
5%*(135-101) or $4.42 = 4.42 + 6%*(135-135)? (Rhetorical.) For most
"percentage method" tables that I've seen, it is a moot point because
there is no difference. But for GA, there is a difference, albeit
insignificant. In any case, my interpretation is that the low-end
title should be treated as "Over", just like similar federal tables.

Also, I apoligize for giving insufficient
information, good thing you are intuitive!

I do not recall commenting on "insufficient" information. On the
contrary, I think your information was more than sufficient. Normally
I avoid providing personal financial details in public postings. If I
must show a complete numerical example, I will choose "hypothetical"
numbers (labeled as such).