Interest Calculator

Estimate interest with transparent assumptions.

Choose compounding frequencyInterest and contributions use the selected number of compounding periods.

4 options

Contribute at the

Initial investment

Annual contribution

Monthly contribution

Interest rate

Investment length

years

Tax rate

Inflation rate

ENDING BALANCE$263,879.35

Total principal: $100,000.00; Total contributions: $60,000.00; Total interest: $103,879.35; Buying power of the end balance after inflation adjustment: $206,142.12. Interest of initial investment: $81,939.67; Interest of the contributions: $21,939.68.

Estimate based on the values shown

Formula checkedCompounds the initial investment and recurring contributions after tax, then adjusts ending buying power for inflation. Separates growth earned by initial principal from growth earned by contributions.

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Useful next steps

$Simple InterestEstimate simple interest with transparent assumptions→$Compound InterestEstimate compound interest with transparent assumptions→%Interest RateEstimate interest rate with transparent assumptions→