Money calculators
Interest calculator
Calculate compound growth from a starting balance, monthly saving, and time. Great when you want to see how small changes affect the final result.
Runs in your browser with no account and no stored data
How it works
Enter a starting balance, a monthly contribution (can be zero), an annual interest rate, and the number of years to project. The total and growth chart update instantly.
Monthly compounding: each month, balance = balance × (1 + annual rate ÷ 12) + monthly contribution.
Starting 10,000, adding 1,000/month at 5% annual over 10 years → about 163,000. Without interest the total would be 130,000.
Comparing savings accounts, projecting pension growth, or seeing how even a small rate difference compounds over time.
What do you want to do next?
Move on to savings goals or percentages if you want to see how a new interest rate or a bigger monthly saving affects the final goal.
Want to see when a goal is reached instead? Open savings goal
FAQ
Is the monthly contribution added before or after interest each month?+
In this model, interest is applied first and the monthly saving is added afterward. That keeps the estimate simple and consistent.
Is the return guaranteed?+
No. The rate you enter is only a scenario, not a promise of actual future performance.
Why do small percentage changes matter so much?+
Over many years, even small differences in return can compound into a much bigger gap because the growth begins to earn growth too.