Calculators

Compound Interest Calculator

Project a lump sum using a fixed nominal annual rate and selected compounding frequency.

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How to use Compound Interest Calculator

The ending balance is principal × (1 + annual rate ÷ periods per year)^(periods per year × years). No additional deposits are included.

Rate must be greater than −100% and at most 1,000%; duration 0–100 years. Fractional compounding periods are modeled mathematically, not as a bank’s posting schedule.
Decimal inputs have at most 120 characters and magnitude from 1e-100 to 1e15, or zero. Floating-point results are rounded to 12 significant digits; extreme derived results may underflow or be rejected. Exact integer results are identified separately.
Educational estimate with user-entered assumptions, not a quote or financial/tax advice. Rates are hypothetical, fixed, and not fetched. Fees, taxes, inflation, payment-day conventions, and currency rules are excluded unless explicitly entered.

What calculation does Compound Interest Calculator perform?

The ending balance is principal × (1 + annual rate ÷ periods per year)^(periods per year × years). No additional deposits are included.

Is the rate an APY?

Enter a nominal annual rate. The effective annual rate can differ because of compounding.

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