Interest Rate Calculator

Solve for the interest rate implied by a loan amount, payment size, and repayment term.

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Input

Enter the principal, repayment term, and payment amount so the calculator can back into the implied borrowing rate. This tool shows the result instantly without step-by-step output.

Input summary

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How to use Interest Rate Calculator

Provide the loan cash-flow details, and the calculator will estimate the rate that makes those payment numbers work mathematically.

What this calculator is for

This calculator is for checking quoted deals, finance homework, and situations where the payment is known but the effective rate is not being stated clearly. It helps expose the rate hidden inside the payment schedule.

Tips

If fees are folded into the payment but not into the principal figure, the implied rate may understate the true borrowing cost.
Use the exact term and payment frequency from the contract because small timing differences affect the solved rate.