Simple Interest Calculator
Calculate simple interest, final value, and year-by-year value changes.
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Your result
Total interest
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Final value
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Interest per full year
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Enter your assumptions to see a short result summary.
Simple interest projection
See how value changes over time when interest is calculated only on the original principal.
Total value
| Year | Starting Value | Interest | Annual Change | Ending Value |
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How it works
- Simple interest is calculated only on the original principal.
- Previously earned interest does not itself earn additional interest.
- When the principal and interest rate stay unchanged, the same amount of interest is added for each full year.
Interest = Principal × Annual Rate × Time
Final Value = Principal + Interest
Frequently asked questions
What is simple interest?
Simple interest calculates interest only on the original principal.
How is simple interest different from compound interest?
Compound interest can earn interest on previously accumulated interest, while simple interest does not.
Can I change the 10-year projection?
Yes. Ten years is only the default display period. You can enter another value.
Disclaimer
This calculator provides estimates for general informational and educational purposes only. Actual financial products may use different day-count conventions, fees, rates, or calculation methods.