Compound Interest Formula! : (

[Tommy_Dolitte]

Anyone have this so I can input into my spreadsheet?

TD

[Marshac]

use the future value (FV) function.

The formula itself is P(1 + rate)^years

Quote:

use the future value (FV) function. The formula itself is P(1 + rate)^years

OK, I used to be OK with math as I am a Software Engineer, but I'm Getting to be an old fart now.

What is "^"

[Marshac]

it's a carrot... yum!

It's just a way of denoting an exponent without the use of supercase.

[Tommy_Dolitte]

Thanks. I used a link I have to a site that provides the results for a weekly contribution @ "x" %---did so for varying inputs, $100, $500, $750, $1000...then I added the exponential trend curve. I'm getting results:

Value = K*e^(0.4967)x

Where K is:

3,297 for $100 weekly contribution
16,487 for $500
24,731 for $750
32,974 for $1,000


Any math whizzes out there?

TD
8)

[bongo2]

I don't understand what you are trying to do. If you are using a constant time frame then the value changes proportionally to the amount that you put in each month. Note that your answer for $1k is exactly twice your answer for $500.

In Excel the function FV() does all this for you, and will work for any interest rate and number of periods. If you know the future value and want to find the payment amound then PMT() is the one you want.

If you are looking for the formula, it's called the annuity formula and you can find it on google.