Compare how your capital would grow with simple and compound interest. Choose USD, EUR or BTC and adjust capital, return, years, and optional contributions.
Compound interest calculator
Compare both results in USD, EUR or BTC, without currency conversion.
Annual reinvestment. Contributions earn proportional returns from the date they are added. Use a return after fees.
Money contributed: 1,000.00 USD
Starting capital: 1,000.00 USD · Additional contributions: 0.00 USD
Without reinvestment · Simple
2,000.00 USDAccumulated profit: 1,000.00 USD
With reinvestment · Compound
2,593.74 USDAccumulated profit: 1,593.74 USD
Reinvestment adds 593.74 USD in this example.
How your money grows
Years · Starting capital, contributions, and accumulated profits, in USD
View the year-by-year calculation
| Year | Contributed (USD) | Simple (USD) | Compound (USD) | Difference (USD) |
|---|---|---|---|---|
| 10 | 1,000.00 | 2,000.00 | 2,593.74 | 593.74 |
How it is calculated
Contributions are added at the end of the months you select. Each earns a return proportional to the time remaining until year-end. The schedule repeats throughout the entire period.
With compound interest, profits are reinvested at the end of each year. With simple interest, they are set aside and do not generate new profits. Both scenarios receive the same contributions.
Money contributed includes starting capital and all contributions. Profit is the final result minus that money.
The eighth wonder of the world?
That is how people often describe the power of compound interest: reinvesting earnings so they become part of the capital that can generate further earnings. With a sustained positive return, time makes that difference grow.
- Simple interest: you earn 100 USD each year on the initial 1,000. You set those earnings aside without reinvesting.
- Compound interest: you earn 100 USD in the first year. You reinvest and begin the second with 1,100; that year’s 10% is 110 USD. You finish with 1,210.
Over 25 years, simple interest totals 3,500 USD in capital and earnings; compound interest reaches 10,834.71 USD. The difference comes from reinvesting.
What to keep in mind
Compound interest describes the effect of reinvesting; it does not guarantee a return. A constant 10% is an assumption for comparison. Trading and investing results vary and cannot be guaranteed.