zippydevtoolsMath
Compound Interest Calculator
Simulate compound interest with monthly contributions, rate conversion, charts, and time-based projections.
- Educational simulation only.
- The result does not replace professional financial advice.
Total invested
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Interest earned
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Final amount
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Run the simulation to see the growth over time.
The projection table will appear after the simulation.
Simulation only. Not investment advice.
10-year projection
Input: $1,000 initial, $200 monthly, 12% yearly rate, 10 years
Output: Summary cards, chart, and projection table.
Compare monthly and yearly rates
Input: Same contribution plan with yearly rate, then monthly rate
Output: Projection shows how equivalent rate conversion changes growth.
How is yearly rate converted to monthly?
The calculator uses exponential equivalence: monthly = (1 + yearly)^(1/12) - 1.
In the simulation, do interest or contributions apply first?
Each month applies interest first and monthly contribution after.
What input limits are enforced?
Monthly rate up to 20%, yearly rate up to 200%, period up to 600 months or 50 years.
Does the tool provide monthly and yearly projections?
Yes. Output includes a monthly series and an aggregated yearly series.
Is this output an investment recommendation?
No. It is a mathematical simulation for educational planning.