calculatorCompound Interest
See how savings grow with monthly contributions and compounding — future value, total contributed and interest earned.
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How It Works
future = if(rate == 0, principal + monthly * years * 12, principal * pow(1 + rate / 1200, years * 12) + monthly * ((pow(1 + rate / 1200, years * 12) - 1) / (rate / 1200)))
principal = 10,000 · monthly = 250 · rate = 6 · years = 20
Live — recalculated with your numbers
Frequently Asked Questions
Monthly. Contributions are added each month and growth compounds on the running balance.
No — results are gross returns. Platform fees and taxes depend on your account and country.
That's your assumption to make. Long-run averages for diversified portfolios are commonly quoted at 5–8% per year — real returns vary year to year.
Version History (1 version)
- v1 7 Jul 2026
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Bookmarked. I check this every time I rebalance my savings.
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The monthly-contribution breakdown is exactly what other calculators miss. Thank you!