Solve for Amortizing Periods

[saxotech]

Hi,

I am having difficulty with this financial equation in one of my apps.

Given:

// E9 Principal Amount (in Dollars)
// D11 Payments per Year (12=Monthly, 26=Bi-Weekly, 52=Weekly)
// D12 Published Interest Rate (i.e. 9% = 0.09)
// D13 Times per Year Interest Calculated (12=Normal/US Mortage 2=CDN Mortgage)

Find:
// D10 Amortization Period (in Years i.e. 6 months = 0.5)

I have looked around everywhere and there are many formulas to solve for Payments (D10) and even some which will solve for the Period of the loan (D10). The problem is, they do not take D13 into account (Times per year interest is compounded).

Does anyone know how to do this or have a formula handy?

Thanks in advance.

[The Hobo]

t = (log(A / P)/log(1 + (r / n))) / n

Where A = Amount, P = Principal, r = rate, n = number of times compounded yearly, and t = # of years.

[saxotech]

Hi, Thanks... i'll try it out!

[prog_tom]

just in case you wonder where he got t from, here is the original form:

A=P(1+r/n)^nt --- compounded n times a year for t years

A=Pe^rt ----- counpounded continuously, where e is Euler's Number, approx. 2.718281828