U.S. money tools
Drop in a 401(k) contribution, savings APY, credit-card APR, or the rent that just went up. Results use standard U.S. compounding math, shown under each panel.
See what a monthly paycheck contribution looks like after years in the market.
Formula: FV = P × [((1+i)^n − 1) / i] × (1+i), where P is the monthly amount, i is the monthly rate, and n is the number of months.
See how a starting balance and monthly deposits grow at a U.S. savings APY.
Contributions and starting balance compound monthly at the annual rate you enter, divided by 12.
Find out how long a balance takes to clear at a fixed payment.
Time to pay off
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Total interest
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Total paid
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Calculated by amortizing the balance month by month: each month's interest is added, then your payment is applied to interest first and principal second.
Enter your balance, rate, and payment, then calculate.
See what today's amount will cost — or be worth — years from now.
Future cost = amount × (1 + rate)^years. Purchasing power = amount ÷ (1 + rate)^years, in today's dollars.
Enter an amount, rate, and duration, then calculate.
The guides library walks through the concepts each calculator is built on.