How to calculate your interest To begin your calculation enter your starting amount along with the annual interest rate and the start date assuming it isnt today. Full usage instructions are in the tips tab below. Principal x rate x time interest For example say you invest 100 the principal at a 5 annual rate for one year.
For interest only use the simple interest calculator.
Also learn more about investments or explore hundreds of other calculators addressing finance math fitness health and many more. Simple Interest Equation Principal Interest A P 1 rt. Understand the variables you need to calculate compound interest. Doing so will calculate the amount that youll have to pay in interest for each period.