Interest rate calculator
Find out what interest rate you are paying from the loan amount, monthly payment and term.
About this calculator
Sometimes you know what you borrowed and what you pay each month, but not the rate. This calculator works backwards from those figures to find the yearly rate that produces your payment, compounded monthly.
It is handy for checking a finance deal, or comparing offers that only show monthly payments.
Common questions
Why does it say the rate would be negative?
If your payments add up to less than the loan, there is no interest at all. Check the amount, payment and number of months.
Is this the APR?
It is the nominal yearly rate. The APR can be slightly higher once fees are included.
More free calculators
Salary calculator
UK take-home pay with tax code, student loan, pension and more.
Income tax calculator
UK income tax and National Insurance for 2026/27.
Mortgage calculator
Monthly payment, total interest and loan to value.
Loan calculator
Monthly payment and total interest on any loan.
Car loan calculator
Monthly payment for a car, with deposit.
Amortisation calculator
Year by year loan schedule showing interest and balance.