Calculate simple and compound interest with online interest and APR calculators. See how varying number of periods and compounding frequency affects nominal interest rate, effective interest rate, periodic and equivalent interest rate calculations.

Simple Interest Plus Principal Calculator

A = P(1 + rt) (Principal + Interest)

Simple Interest Calculator

I = Prt (Interest Only)

Compound Interest Calculator

A = P(1 + r)^t   and  A = P(1 + r/n)^nt   and  A = Pe^rt

Periodic Compound Interest Calculator

Excel Function Method for A = P(1 + r)^t

APR: Annual Percentage Rate Calculator

Effective Annual Rate (EAR) Calculator

i = (1 + r/m)^m − 1

Effective Interest Rate Calculator

Nominal Interest Rate Calculator

Periodic Interest Rate Calculator

Equivalent Interest Rate Calculator

Interest Rate Table