Question: how to do nper in excel?
Answer: Summary. ... 
Get number of periods for loan or investment.
The number of periods.
=NPER (rate, pmt, pv, [fv], [type])
rate - The interest rate per period. ... 
You can use the NPER function to get the number of payment periods for a loan (or an investment), given the amount, the interest rate, and a periodic payment amount.