Not financial advice. This tool gives general information, not financial advice. Results are estimates; check figures with your lender, employer or a licensed financial professional before making money decisions. Full disclaimer.
Precision · Instant · Private
Compound Interest Calculator
See how savings grow with compound interest and regular contributions. Enter a starting amount, rate, and time to project your future balance.
SYSTEM ● ONLINE · LOCAL COMPUTE · ZERO UPLOAD
Figures are in whatever currency you enter. The calculator does not convert between currencies, and the worked examples below are examples, not amounts in any particular one.
UNIT // COMPOUND.INTLIVE
Future balance
144,573
Contributed 58,000 · Interest 86,573
144,573
Future value
58,000
Contributed
86,573
Interest earned
Quick Answer
What is compound interest?
// Answer
Compound interest is interest earned on both your original money and the interest it has already earned. Over time this creates exponential growth. With regular monthly contributions, the effect is even stronger — this calculator compounds monthly and adds your contributions along the way.
Why time matters most
The earlier you start, the more compounding works in your favor. At the same rate, a dollar invested at 25 has grown far more by 65 than a dollar invested at 45, because it has had two extra decades to compound. Larger amounts invested later can still catch up, so try both in the calculator.
Why use this tool
Project your savings
Model retirement savings, an emergency fund, or any long-term goal. Adjust the rate and time to see the dramatic effect of compounding. Returns are illustrative, not guaranteed — real investments fluctuate. This is not financial advice.
FAQ
Frequently asked questions
Simple interest is calculated only on the principal. Compound interest is calculated on the principal plus accumulated interest, so it grows faster.
Monthly, to match the monthly contributions. Real savings accounts compound daily, monthly, quarterly or yearly depending on the account, and investments do not grow at a fixed rate at all.
No. The calculator shows a projection at a fixed rate. Real investment returns vary year to year.