NPER

Returns the number of periods required to pay off a loan, for a constant periodic payment
and a constant interest rate.
=NPER(B1/B2, B3, B4)
NPER() Result is 10.33803507150767
=NPER(C1/C2, C3, C4, C5, C6)
NPER() Result is 52.79477370927476