Read HELP on Financial Functions...FV,PV,PMT etc etc
While you can of course design your own User Defined Functions, there's
little point in replication what's already available as a spreadsheet
function.

From HELP:

NPER
Returns the number of periods for an investment based on periodic, constant
payments and a constant interest rate.

Syntax

NPER(rate, pmt, pv, fv, type)


"sirsoto" wrote:

Hi, I have a formula that I would like to put into excel but I dont know how
to solve for t. This one is a toughy

I am trying to solve for t, time.

FV = future value
R = f*p
i = 0.05
t mod 2 = remainder which = t €“ 2k
t = ?



FV = 2R (((1+i)^t -1)/i) + R (1+i)^t (t mod 2)


This formula was designed to return the time it will take to pay off an
investment whereby the revenues received, R, increase every two years by
percent i