Need to make a monthly amortization schedule. Borrowing 16000 over 4 years at 3.5%. Do I need to calculate for 48 months in order to do this project correctly? I do all the calcs for 48 months and I still end up with approx a payment left over?

16000 = paym (1 - (1.00291666..)^-48)/.00291666..

I got payment = 357.70

# Paym - Inter- Repaym - Balance
0 000.00 00.00 000.00 16000.00
1 357.70 46.67 311.03 15688.97
2 357.70 45.76 311.94 15377.03
...
..
48 357.70 1.04 356.67 -0.72

done with Excel, error due to roundoff of original payment
Make sure you carry enough decimals of
.002916666... in your calculator, I did .035/12 and then stored that result in memory.