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CalcMyCompound

Frequently Asked Questions

Compound interest is interest calculated on both the initial principal and the accumulated interest from previous periods. Unlike simple interest — which is calculated only on your original deposit — compound interest lets your money earn interest on its interest, creating an exponential growth curve over time.
Initial Investment (Principal): 10,000 USD · Annual Interest Rate (%): 7% · Investment Period: 10 · Monthly (12/year) → 20,096.61 USD. Illustrative assumptions. Rates are constant; results are not a forecast.
Calculate interest on the original principal, with a yearly breakdown. I = P × r × t; A = P + I.
Compound interest is interest calculated on both the initial principal and the accumulated interest from previous periods. Unlike simple interest — which is calculated only on your original deposit — compound interest lets your money earn interest on its interest, creating an exponential growth curve over time. Daily (365/year), Monthly (12/year), Quarterly (4/year), Annually (1/year)
Dividing 72 by a positive annual rate gives an approximate doubling time in years. This is a shortcut, not an exact calculation or a forecast.
Interest can also accumulate on debt. Repayments and contract terms affect the balance; this savings model does not simulate credit-card repayment rules.
Illustrative assumptions. Rates are constant; results are not a forecast. Monthly contributions earn the equivalent monthly yield. Tax is applied once to positive gains at the end; fees are excluded.
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Monthly contributions earn the equivalent monthly yield. Tax is applied once to positive gains at the end; fees are excluded.
Illustrative assumptions. Rates are constant; results are not a forecast.
Enter valid amounts. Rate: greater than −100% to 100%; inflation and tax: 0–100%.