Compound interest calculator
See what a balance grows to with regular deposits, any compounding frequency, and inflation in today’s money.
Interest rates are assumed fixed and tax is not deducted. Real savings rates move, and what is taxable depends on your country and account type.
How this is worked out
A = P(1 + r/n)^(nt) + PMT × [((1 + i)^(mt) − 1) ÷ i]What this assumes
A calculator is only as good as what it leaves out. These are the assumptions built into the result above.
- The interest rate is fixed for the whole period. Real savings rates move.
- Deposits are made at the end of each period unless you switch to the start.
- Tax on interest is not deducted. What is taxable depends on your country and account type.
- Inflation, when entered, discounts the final figure into today’s money.
Educational information only. This page explains how something works in the United States. It is not financial advice and does not take account of your circumstances. Rates, fees and eligibility change without notice — check the provider’s own terms before you act.
For free, impartial guidance, see Consumer Financial Protection Bureau. To complain about a firm, contact the CFPB complaint database.
Guides that go with this tool
High-Yield Savings Accounts: What to Look For
What makes an account high-yield, what the advertised APY may be hiding, and when a savings account beats a CD.
Compound Interest: How It Actually Works
Compound interest is interest earning interest. The mechanism is simple, the effect is not linear, and it works against you on debt exactly as it works for you on savings.
Emergency Funds: How Much and Where to Keep It
What an emergency fund is for, how to size one for your situation, and why the account you keep it in matters more than the rate it pays.