mileage sheet change in percentages

[bricktop]

hello to all ,
I am trying to make a mileage sheet for my work and i cant seem to wor
out how to change percentage rate after a certain amount of miles ar
reached. The percentage rate of 40% is needed for the first 10,00
miles total and thereafter any more miles are to be charged at 25%. Th
first 10,000 is easy to do but i cant seem to figure a way to change i
over to 25% bearing in mind it can not be on the total of the firs
10,000 miles only on the miles after. Any help or ideas would b
appreciated thx.
I will try and attach the sheet i have started on

 

[Peo Sjoblom]

One way, courtesy of J.E. McGimpsey

=SUMPRODUCT(--(A1>{0;10000}),(A1-{0;10000}),{0.4;-0.15})

where A1 holds your mileage
will return 40% of the first 10000 and 25% above thus 20000 miles will
return 6500

taken from

http://www.mcgimpsey.com/excel/taxvariablerate.html