Numbers
Compound Interest Generator
Used by developers, writers, and creators worldwide.
A compound interest generator shows how a starting amount grows over time when interest is reinvested rather than paid out. Enter your principal, the annual interest rate, how many years you plan to leave the money invested, and how often interest compounds, and it lists the balance at the end of each year plus the total interest earned. Compounding is what makes long-term saving powerful: each period you earn interest on your interest, so the balance accelerates as the years pass. Savers use this to picture how a pension or savings account might grow, students to study the formula behind exponential growth, and anyone comparing accounts to see how compounding frequency changes the outcome. Everything is calculated instantly in your browser using the standard compound interest formula. The figures are illustrative and ignore tax, fees, and inflation, so treat them as a clear estimate rather than financial advice.
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How to use
- Choose your options above
- Click Generate
- Copy your result
Detailed instructions
- Enter your starting amount and the annual interest rate.
- Set how many years the money stays invested.
- Choose how often interest compounds per year.
- Click Generate to see the balance for each year and the total interest.
Use Cases
- •Estimating how a savings account or pension might grow over time
- •Comparing accounts with different compounding frequencies
- •Teaching the compound interest formula with a worked example
- •Setting a long-term savings goal and seeing the yearly milestones
- •Understanding how exponential growth accelerates in later years
Tips
- →Increase the compounding frequency to see how it nudges the final balance up.
- →Longer time horizons show the dramatic acceleration of compounding.
- →Compare two rates by running the tool twice and noting the difference.
- →Remember the figures are gross — real returns are lower after tax and inflation.
FAQ
how is compound interest calculated
It uses the formula A = P(1 + r/n)^(nt), where P is the principal, r is the annual rate as a decimal, n is the number of times interest compounds per year, and t is the number of years. The tool applies this for each year so you can see the balance build.
why does compounding frequency matter
The more often interest compounds, the sooner you earn interest on interest. Monthly compounding produces a slightly higher balance than annual compounding at the same rate, because each smaller period adds to the base the next period grows from.
does this account for tax or inflation
No. The figures are gross and illustrative — they ignore tax, fees, and inflation, all of which reduce real returns. Use the result to understand the mechanics of compounding, not as financial advice for a specific product.