Help! I need to calculate interest based on monthly rate!

[jmarc23]

Hi there. I need create a spreadsheet that calculates based on a monthly interest rate. I have the principal amount, the rate (1.5% per month) but I'm having difficulty trying to formulate the time.

This is the formula I'm using on my spreadsheet: I= PxRxT

But I can't figure out how to input time...

For instance, the first entry is $1,500.00 beginning September 15, 2008. I need to calculate the interest based on 1.5% monthly to today's date. I can do it monthly, but the days that straggle is what is getting me. I may be overthinking it.

Please help! Let me know if you need any more information.

Thanks,

J.

 

[CharlesChuckieCharles]

Does it compound?


If It doesn't then

(Principle * ((monthlyRate*12)/365)*(Today-15/09/2008))

 

[CharlesChuckieCharles]

Did That do what you wanted?

 

[jmarc23]

It did! Thanks for your help!