Why would I need to solve for the rate?

Useful when you know your loan amount, payment, and term (e.g., from an offer or existing loan) but the interest rate wasn’t clearly stated.

Interest Rate Calculator

Banking & Interest

Solve for the interest rate implied by a loan’s principal, payment, and term.

Display currency

Changing the display currency only changes the symbol shown — amounts aren't converted, since this tool doesn't use live exchange rates.

Loan amount

Monthly payment

Term (years)

Implied annual interest rate

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How this is calculated

Solves numerically (bisection) for the annual interest rate that makes the standard amortization formula produce the exact monthly payment you entered — the reverse of a normal loan payment calculation.

Frequently asked questions

Why would I need to solve for the rate?: Useful when you know your loan amount, payment, and term (e.g., from an offer or existing loan) but the interest rate wasn’t clearly stated.

Loan Calculator

Calculate the monthly payment and full amortization schedule for any fixed-rate loan.

APR Calculator

Calculate a loan’s true APR by factoring in upfront fees on top of the stated interest rate.

Effective Interest Rate Calculator

Calculate the true effective annual rate of a loan once compounding frequency is factored in.