Your formula makes no sense, as the

(NPT Hours/(NPT Hours*24))*100)

will always result in 4.166667 for non-zero NPT.


How are you really calculating your percentage?


In article ,
Peledon wrote:

If I have for instance 31 days in March which has 8.75 days of NPT this
equals 1.18%, calculated using the following formula.
=IF(Total Days="","",(NPT Hours/(NPT Hours*24))*100) = 1.8%.

What if I only know ther percentage 1.8% and Number of Days in Month 31
days. How do I calculate this to get the number of days NPT?