Wyvek

Compound Interest Calculator

See how savings grow over time.

Final balance —
Total deposited —
Total interest earned —

Estimate only — figures exclude taxes, fees, and rate changes, and may differ from your provider’s. The currency symbol is illustrative.

Free online compound interest calculator

This compound interest calculator shows how a savings or investment balance grows over time as interest earns interest. Enter your initial principal, the annual interest rate, the term in years, and how often interest compounds — and optionally an amount you add each period — and the final balance, total deposited, and total interest update instantly. It is ideal for planning savings goals, comparing accounts, or seeing the long-term power of regular investing.

How to calculate compound interest

  1. Enter your initial principal — the amount you start with.
  2. Enter the annual interest rate as a percentage, such as 5.
  3. Set the term in years and pick a compounding frequency.
  4. Optionally add a contribution made at the end of each period.
  5. Read the final balance, total deposited, and total interest earned.

Understanding your results

The final balance is your projected total at the end of the term. Total deposited is your own money — the principal plus every contribution — while total interest earned is the growth on top of that. Compounding more often, saving for longer, or adding regular contributions all increase the interest you earn.

Related tools

Planning to borrow instead of save? Estimate repayments with the loan calculator, or crunch quick percentages with the percentage calculator. Like every tool here, this calculator runs fully in your browser — nothing you type is uploaded.

Frequently asked questions

How is compound interest calculated?

The principal grows using A = P · (1 + r/n)ⁿᵗ, where P is the initial amount, r is the annual rate as a decimal, n is the number of times interest compounds per year, and t is the number of years. Regular contributions are added as an ordinary annuity — each deposit is made at the end of a compounding period and earns interest for the remaining periods. The final balance is the grown principal plus the future value of all contributions. Everything is computed live in your browser.

What does compounding frequency change?

Compounding frequency is how often interest is added to your balance. The more frequently interest compounds — annually, semi-annually, quarterly, monthly, or daily — the more often you earn interest on previously earned interest, so a higher frequency produces a slightly larger final balance at the same annual rate.

How are regular contributions treated?

The optional contribution is added once at the end of every compounding period. If you compound monthly, one contribution is added each month; if you compound annually, one is added each year. Because each deposit lands at period end (an ordinary annuity), the most recent contributions earn little or no interest, while the earliest ones compound the longest.

What is the difference between total deposited and total interest?

Total deposited is the money you actually put in — your initial principal plus every contribution you make. Total interest earned is the final balance minus everything you deposited, showing how much your money grew on its own. Together they add up to the final balance.

Is the result exact and what currency is it in?

The math is precise, but real accounts may use different compounding conventions, rounding, fees, taxes, or variable rates, so treat the figures as an estimate. The dollar symbol is illustrative only — the calculation is currency-neutral, so read the numbers in whatever currency you entered.

Is my financial information sent anywhere?

No. This compound interest calculator runs entirely in your browser using JavaScript. The amounts, rate, term, and contributions you enter are never uploaded or stored, so it is safe for private financial planning.

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