Put the amount you want to end up with in this box.
For example, if the amount is $1500, put 1500 without the dollar sign in the box.

Next, put in this box the annual interest rate.
If the interest rate is 5.25% put 5.25 in the box without the % sign.

Next, choose how often you wanted the interest compounded. daily monthly quarterly semi-annually annually

Finally, choose how many years you want the money to sit for.

And click this button.

You can do this again with different numbers. Just hit the clear button.