FINANCE

Compound Interest Calculator

Estimate compound balance from principal, annual rate, term with the Compound Interest Calculator.

Choose an interest resultCompare compound growth, compound interest earned, and simple interest.

3 options

Principal

Annual rate

Term

years

COMPOUND BALANCE$179,084.77

P(1+r)ᵗ. The selected operation controls which fields and formula are used.

Estimate based on the values shown

MethodSwitch between compound balance, earned interest, and simple balance.

Before you use the result

Planning estimate only. Rates, fees, taxes, eligibility rules, timing, and provider terms can change the result.

Sources

Compound Interest CalculatorInvestor.gov, U.S. Securities and Exchange Commission

EDITORIAL NOTES

Using the Compound Interest Calculator responsibly

Page-specific guidance based on this calculator’s implemented method, inputs, and known limits.

What this result is useful for

This tool shows how an opening balance and recurring contributions may grow when returns compound. It is most useful for comparing contribution timing, frequency, rate, and duration, not for predicting a particular investment outcome.

Assumptions and limits

The entered rate is treated as constant, contributions follow the selected schedule, and displayed growth is mathematical rather than guaranteed. Market volatility, investment fees, taxes, inflation, contribution limits, and sequence-of-returns risk can materially change real results.

How to check the result

First set the rate to zero and confirm that the result equals the starting balance plus contributions. Then compare annual and monthly compounding using identical cash flows. If this supports a real decision, repeat the scenario with lower returns and explicit fees.

CALCULATOR GUIDE

How to use the Compound Interest Calculator

Estimate compound balance from principal, annual rate, term with the Compound Interest Calculator. It includes Compound balance, Compound interest, Simple balance workflows, so choose the one that matches the values you actually know. Use it as a planning baseline, then compare the estimate with current rates, fees, taxes, and provider terms.

Step by step

For the Compound Interest example, select Compound balance and enter principal, annual rate, term. Keep each value in the unit displayed beside its field.
Review the selected Compound Interest workflow and inputs, then read compound balance in the result panel.
Change one Compound Interest assumption at a time to compare scenarios. Use Reset to restore this tool's worked example values.

How the calculation works

Switch between compound balance, earned interest, and simple balance.

Worked example

To reproduce the Compound Interest worked example, reset the calculator. Select the Compound balance workflow. Use principal $100,000; annual rate 6 %; term 10. The result is compound balance of $179,084.77. P(1+r)ᵗ. Review the displayed units before comparing the result.

Understanding the result

The Compound Interest reports compound balance. Use it as a planning baseline, then compare the estimate with current rates, fees, taxes, and provider terms. Planning estimate only. Rates, fees, taxes, eligibility rules, timing, and provider terms can change the result.

How to check the answer

Check the Compound Interest result by entering the same principal, annual rate, term in an independent statement, lender, provider, or official tool. Change one input and confirm that compound balance moves in the direction implied by Switch between compound balance, earned interest, and simple balance.

Common questions

What does the Compound Interest calculate?

Estimate compound balance from principal, annual rate, term with the Compound Interest Calculator.

Which inputs does the Compound Interest example use?

The worked example uses principal, annual rate, term in the Compound balance workflow. Other workflows can show different fields. Keep the chosen workflow and units with the result when comparing calculations.

Is the Compound Interest result exact?

Planning estimate only. Rates, fees, taxes, eligibility rules, timing, and provider terms can change the result. Recheck principal, annual rate, term and use compound balance only for a decision where that level of precision is appropriate.

INTERPRET THE RESULTRead the finance guideCheck assumptions, limitations and comparison methods →

KEEP GOING

Useful next steps

InterestEstimate ending balance from initial investment, annual contribution, monthly contribution with the Interest Calculator.Simple InterestEstimate end balance from principal, interest rate, term with the Simple Interest Calculator.Future ValueEstimate future value from number of periods (n), starting amount (pv), interest rate (i or y) with the Future Value Calculator.