The Interest Rate Calculator determines real interest rates on loans with fixed terms and monthly payments. For example, it can calculate interest rates in situations where car dealers only provide monthly payment information and total price without including the actual rate on the car loan.
Modify the values and click the calculate button to use
A payment-based interest-rate calculation solves the loan payment equation for the unknown rate. Payment amount, principal, number of periods and payment timing must describe the same loan.
Example to check
For a one-period loan of $1,000 repaid with $1,050, the interest for that period is $50, or 5%. A monthly period does not make that a 5% annual rate.
Before using the result
A solved interest rate can exclude origination fees, insurance and other charges. It is not necessarily a legally disclosed APR; confirm rate conventions before comparing lenders.