Finance
Compound Interest Calculator
Project growth of savings with compound interest.
Future value
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Total contributions
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Total interest earned
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FAQ
- What formula is used for compound interest?
- Future value of principal: FV = P * (1 + r/m)^(m*t), where P is principal, r is annual rate, m is compounding periods per year, and t is years. Monthly contributions use the future value of an ordinary annuity: C * ((1 + r/m)^(m*t) - 1) / (r/m). Both are summed for the total.
- How does compounding frequency affect growth?
- More frequent compounding (daily vs. yearly) results in slightly higher returns because interest is earned on interest sooner. For example, $10,000 at 8% for 10 years compounds to $21,589 annually vs. $22,196 daily — a meaningful difference over long horizons.
- Is my data sent anywhere?
- No. All calculations run entirely in your browser. Nothing is transmitted to any server.