Web Simple and Compount Interest Calculator - Free Online Simple and Compount Interest Calculator

Calculating interest rates can be a pain, but with our calculators it can be painless! Come use our free, online simple interest and compount interest calculators! Input the numbers and find out how much interest you will accrue, we'll even have a graph so that you can see your interest vs your principal.

Simple Interest Formula

Simple interest compared to compound interest is easily calculated by using the formula:

I = Prt

Here the variables represent:

  • I = interest amount
  • P = principle amount
  • r = annual interest rate
  • t = time

Plug in all your values and solve for the variable that you need.

Compount Interest Formula

Compound interest is calculated by using a slightly more complicated formula:

A = P(1 + r/n)^{(nt)}

In this formula, the variables represent:

  • I = interest amount
  • P = principle amount
  • r = annual interest rate
  • n = number of compounds per time period
  • t = time

Plug in all your values and solve for the variable that you need.