How does Find Rate work?

It uses a bisection algorithm to find the monthly rate where the payment formula exactly matches your actual payment, then converts to an annual rate.

Can I enter the term in years?

Enter the term in months: multiply years × 12 (e.g. 30 years = 360 months).

Does this include fees?

No, this calculates the pure interest rate. To include fees, use the APR Calculator.

Is this the same as APR?

Not necessarily. APR includes fees and other costs; this tool calculates the nominal interest rate from payment data only.

INTEREST RATE CALCULATOR

Find the interest rate behind a loan from its payment and term, or calculate the monthly payment from a rate. All math runs in your browser — nothing is sent anywhere.

Loan Amount ($)

Monthly Payment ($)

Loan Term (months)

Annual Interest Rate4.40%0.3664% / month

Total Interest Paid$130,000.00

Total Amount Paid$330,000.00

How to use the interest rate calculator

1
Choose a mode: find the interest rate from your payments, or find the monthly payment from a rate.
2
Enter the loan amount and term in months.
3
In Find Rate mode, enter your actual monthly payment. In Find Payment mode, enter the annual interest rate.
4
Read the result — interest rate, monthly payment, and total interest paid.

Questions

How does Find Rate work?: It uses a bisection algorithm to find the monthly rate where the payment formula exactly matches your actual payment, then converts to an annual rate.
Can I enter the term in years?: Enter the term in months: multiply years × 12 (e.g. 30 years = 360 months).
Does this include fees?: No, this calculates the pure interest rate. To include fees, use the APR Calculator.
Is this the same as APR?: Not necessarily. APR includes fees and other costs; this tool calculates the nominal interest rate from payment data only.