Example 1 — 10 years at 6%
- Principal: 10,000
- Rate: 6%
- Years: 10
Final ≈ 17,908.48
Interest ≈ 7,908.48
A decade of compounding nearly doubles the capital at 6%.
Compound interest
Compute future capital with annual compounding — interest joins the base and earns further interest.
Educational model: final = principal × (1 + rate/100)^years (once-a-year compounding). No mid-term deposits, fees, or tax. Amounts follow the header currency.
Result
Enter data and click Calculate.
How results are calculated
Compound interest means interest joins the principal and itself earns interest in later years (“interest on interest”).
Final amount = principal × (1 + rate/100)years, shown in the header currency.
Total interest = final − principal. Multiple = final ÷ principal; % gain = interest ÷ principal × 100%.
How to use the calculator
- Enter the starting principal in the header currency.
- Enter the annual rate in percent.
- Set the number of years (once-a-year compounding).
- Read the final amount, interest, growth multiple, and the year-by-year table.
Usage examples
Example 2 — 5 years at 5%
- Principal: 25,000
- Rate: 5%
- Years: 5
Final ≈ 31,907.04
A shorter horizon yields less compounding effect despite a larger principal.
Example 3 — 15 years at 8%
- Principal: 5,000
- Rate: 8%
- Years: 15
Final ≈ 15,860.85
A long horizon and higher rate strongly multiply a smaller principal.
FAQ
What does compound interest compute?
Future capital value with compounding: interest joins the base and earns further interest. Result in the header currency after n periods.
When is compounding the right model?
When funds stay invested and compounding actually occurs (yearly, monthly, etc.) as in the product terms.
What does the model omit?
Contributions or withdrawals mid-term, a changing rate, and account fees. It is pure compounding at a fixed rate.
What mistake inflates the result?
Entering an already-effective rate while also selecting many compounding periods per year — double compounding.
What formula does this calculator use?
Final = principal × (1 + rate/100)^years — once-a-year compounding at a fixed rate.
How does it differ from simple interest?
With simple interest the base stays flat. Here interest joins the principal and earns in later years.
Which related tools help next?
Deposit gain, savings interest, and inflation — to compare a bank product, simple earnings, and real purchasing power.
When should you not use this model?
When you have regular contributions, a changing rate, or monthly/daily compounding — then this is only an approximation.