Free calculators and unit converters for general and everyday use.
Our online tools will provide quick answers to your calculation and conversion needs. On this page, you can calculate effective interest rate or effective annual rate (EAR) given nominal interest rate of a loan or financial instrument.
The effective interest rate r is calculated using the following formula:
r = (1 + i/n)n - 1
i = nominal rate
n = number of compounding periods per year
This calculator is especially useful for figuring out the real cost of credit-card borrowings.