Count number of days from the last entry?

[MD]

I need a formula to count the number of days from TODAY() to the last entry
in column "J".
Column "A" is date column.

 

[Max]

This will grab the date in col A corresponding to the last entry in col J
=LOOKUP(2,1/(J2:J100<>""),A2:A100)

Hence you could use this:
=TODAY()-LOOKUP(2,1/(J2:J100<>""),A2:A100)

Adapt the ranges to suit

 

[MD]

Many thanks Max that works ok

This will grab the date in col A corresponding to the last entry in col J
=LOOKUP(2,1/(J2:J100<>""),A2:A100)

Hence you could use this:
=TODAY()-LOOKUP(2,1/(J2:J100<>""),A2:A100)

Adapt the ranges to suit