Compound Interest & Savings Growth
See how your savings grow over time, how much is interest, and what it will actually be worth after inflation. Inflation rates load live from the World Bank, and you can override anything.
Your plan
Results
Growth over time
Year-by-year breakdown
| Year | Contributions | Interest | Balance | Today's money |
|---|
About this calculator
Compound interest means you earn returns on your returns. Each month your balance grows by the periodic rate and your contribution is added. The "worth in today's money" figure discounts the final balance by inflation so you can see real buying power, not just a big headline number. Live inflation is the World Bank's consumer-price figure for the country you choose; it is an assumption about the future, so adjust it to your own view. This is general information, not financial advice.
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How to use Compound Interest & Savings Growth
Enter your figures
Fill in Starting amount, Monthly contribution, Currency symbol and Annual interest / return %. Values you change are used straight away, with no submit button.
Adjust the assumptions
Fine-tune Years, Compounding, Inflation rate % (yearly) and Inflation reference country to match your own situation.
Read the results
The Your plan, Results and Growth over time update as soon as a value changes.
What this tool does
Compound interest with monthly contributions
A starting amount and a monthly contribution are both compounded forward, and the result separates what you put in from what the interest added.
Choose compounding frequency
Compounding can be monthly, quarterly or annually, which changes the final figure more than most people expect.
Live inflation rates from the World Bank
Inflation rates load from the World Bank's public data for the country you choose, and you can type your own number over the top.
Inflation-adjusted (real) future value
The inflation-adjusted figure is what the balance would buy in today's money, which is usually the number that actually matters.
Growth chart and yearly breakdown
A growth chart shows the curve and a table gives the year-by-year balance, so you can see the point where interest starts outpacing contributions.
Frequently asked questions
How is compound interest calculated here?
The standard formula A = P(1 + r/n)^(nt), with monthly contributions added on top and compounded from the month they go in. You choose the compounding frequency, so monthly, quarterly and yearly all give different results.
Where do the inflation rates come from?
They load live from the World Bank's public data for the country you pick. You can override the rate with your own number if you would rather model a specific assumption.
What does the inflation-adjusted figure mean?
It is what your final balance would buy in today's money. A balance of 100,000 in 20 years at 3 percent inflation is worth about 55,000 in today's terms, which is usually the number that matters.
Does it include tax on interest?
No. The result is before any tax on interest or gains, because rates and allowances differ by country. Reduce your interest rate to model tax roughly.
Is anything I enter uploaded?
No. The calculation runs in your browser. The only network request is the one that fetches published inflation rates, and it sends none of your figures.
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