Investing
Compound interest calculator
Estimate how an initial amount and regular monthly contributions may grow over time. Change the rate, term and currency to compare scenarios.
Estimated future value
$106,639
Your contributions
$70,000
Estimated return
$36,639
Growth over time
Year
This is an illustrative calculation, not a forecast or financial advice. Actual returns may vary.
Formula
How compound interest is calculated
Compound interest means that each period's return is added to the balance, so future returns are calculated on both your contributions and earlier returns.
In the formula, P is the starting amount, PMT is the regular contribution, r is the monthly rate and n is the number of months. The calculator assumes the contribution is made at the end of each month.
Frequently asked questions
Does the selected currency change the calculation?
No. Currency only changes number formatting. The same formula works for dollars, euros, rubles and other currencies.
Are taxes and investment fees included?
No. Enter a rate that already reflects the fees or taxes you want to model.
Is the result a guaranteed return?
No. It is a mathematical scenario based on a constant rate. Real investment returns change over time.