Interest & Savings Calculator
Model compound growth with regular monthly savings.
Your numbers,
in plain sight.
Enter your details and calculate to see your breakdown.
Separate your deposits from growth
Enter an initial balance, a monthly deposit, an annual rate and the number of years. Compare the total deposited with the illustrative interest instead of treating the whole balance as profit.
Worked example
With $10,000 initially, $200 deposited each month, 4% a year and ten years, the model gives $44,358.29. Your deposits total $34,000; the remainder is illustrative growth before tax and fees.
How the result is built
The annual rate is divided by 12 for monthly compounding. Each regular deposit arrives at the end of the month, so it does not earn interest for that month.
Before you use the number
This is not a quoted product or an expected investment return. Tax, fees, inflation, variable returns and withdrawals can change the outcome.
Why does deposit timing matter?
Money added at the start of a month earns an extra month of interest compared with an end-of-month deposit. Compare products using the same timing assumptions.
How we prepare and correct content · Model reviewed 26 September 2026. Examples are illustrative.
Useful estimates. Clear assumptions.
A fixed interest rate is assumed throughout. Savings deposits are made at the end of each month; fees, investment tax, inflation and changing rates are excluded. Mortgage payments are monthly and no extra repayments are assumed.
See calculation rules & official sources ↗Your next useful calculation.
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