Simple vs Compound Calculator
Simple vs Compound Interest Calculator
Compare how much extra growth compound interest may produce versus simple interest over the same time period.
Outputs
Results
Enter your numbers and click calculate.
Year-by-year table
A yearly summary of balance, contributions and interest.
| Year | Deposits | Withdrawals | Interest | Tax / fees | End balance |
|---|
What if I allow five more years?
Calculate to see the comparison.
Simple vs compound interest
Calculate to see the comparison.
Excel formula
A matching FV formula is available for constant monthly payments without tax, fees or account exhaustion. Annual and increasing payments require the exported schedule. Inflation adjustment is separate.
=FV(...)Growth chart
Compare your balance, net cash paid in and net growth or loss after deductions. Negative returns remain visible.
Month-by-month table
Click a year to expand the monthly breakdown.
Guide
A consistent simple-versus-compound comparison
For £10,000 at 5% for ten years with no payments or deductions, simple interest produces £15,000. Monthly compounding of the same nominal annual rate produces approximately £16,470.09.
The results compare both methods using the same requested cash-flow dates and tax/fee settings. Simple interest earns no return on previously earned interest; new deposits can earn simple interest for the time they remain invested. Withdrawals and fees reduce contributed capital proportionally. If an account runs out of money, actual fulfilled withdrawals can differ. See the simple and compound interest guide.
How this calculator works
Simple interest is calculated only on the original amount. Compound interest adds earned interest back into the balance, so the next period earns interest on a larger amount. The results panel includes a simple versus compound comparison automatically.
You can still change every input: currency, interest rate, years and months, compounding frequency, contribution timing, inflation and tax or fees. Use the share URL button to save a pre-filled version of the result.
FAQ