
FORMULA for a LOAN
I need to know how to calculate loan payments...
like if i borrow $100,000 at 6.5% APR for 15years what is my per month charge?  I need to know the math formula or just some code since I need to do this via PHP or Javascript...
It seems like a simple problem but I get stuck on this... I've seen some payment forms in javascript and they use loops that are complicated to understand...
I need to know how much I will pay in total after 15years or whatever payment period lasts and I need to know the monthly bill...
Remember, I think that the APR is calculated on the principal owed so as you pay the principal is reduced and tapers off 
I don't want 100,000 * (1.065^15), that's not how loans work...

the formula for monthly payments is:
Code:
A

(1  (1 + I) ^ N

I
the numerator is A, and the denominator is below everything below A.
or
Code:
A / ((1  (1 + I) ^ ( N)) / I)
This is coming from my calculator, so readability is a bit tedious.
A is the loan amount.
I is the interest rate in decimal form divided by 12 (for monthly), i.e. .065 / 12 for 6.5%.
N is the number of months, i.e. 360 months for 30 yrs.
and yes, that is a negative N, just incase it is a bit small to read.
for total amount including interest, just multiply monthly payments by number of months.
edited for correctness of I.

Thank you very much sir!!!
