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Compound Interest Calculator

Project a balance with interest frequency and optional deposits.Calculators

Compound Interest Calculator

Project a balance with compound interest and optional regular contributions. Contributions are added at the end of each compounding period.

Added at the end of each compounding period.

Final amount
1647.01
Interest earned
647.01
Total contributions
0.00

This is a projection, not financial advice. Real returns depend on taxes, fees and rate changes.

About this tool

Compounding frequency changes the outcome, and so do regular contributions. This calculator simulates period by period — not just a closed formula — so deposits are applied at the right moments and the interest total is exact for the inputs you give.

How to use the Compound Interest Calculator tool

  1. Enter the principal and rate. The starting balance and the nominal annual interest rate.
  2. Choose term and frequency. Years, plus yearly, half-yearly, quarterly, monthly or daily compounding.
  3. Add contributions (optional). A fixed deposit at the end of each compounding period, if you make one.

Supported formats

Input

  • Principal, annual rate and term
  • Compounding frequency
  • Optional contribution per period

Output

  • Final amount
  • Total interest earned
  • Total contributions

Inputs are validated before anything is processed. Invalid values and unsupported files are rejected with a clear error instead of failing silently.

Frequently asked questions

Why simulate instead of using the closed formula?

Contributions compounding at the right moments require the period-by-period calculation; the simulation is exact for the stated assumptions.

Which frequency grows fastest?

More frequent compounding yields slightly more; the difference is small at typical rates.

Are taxes or fees modelled?

No. The projection is nominal and pre-tax.

Is this financial advice?

No. It is arithmetic on your inputs; real products differ in fees, rate changes and timing.

Privacy

Everything you enter stays in this browser tab. There is no upload endpoint for tool inputs, no account, and no server-side copy of your text or files. Results are produced locally and disappear when you close the page.

No account is required and no file is ever uploaded. See the privacy policy for details about analytics and the limited data this site stores.

Known limitations

  • A fixed rate and fixed contributions are assumed for the whole term.
  • No tax, fee or inflation adjustment.
  • Daily compounding uses 365 periods per year, ignoring leap days.

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