Home / Calculators / Finance / Simple Interest Calculator

Simple Interest Calculator

Calculate interest earned or owed on the original principal only.

Principal ($)Annual rate (%)Years

Frequently asked questions

What is the simple interest formula?

Interest = principal × rate × time.

See how savings grow with monthly compounding and contributions.

Check your DTI ratio, which lenders use to judge borrowing capacity.

Project your savings balance and time to reach a goal.

See how inflation erodes the buying power of your money over time.

Compute the discount amount, sale price and total savings from any original price, with an optional extra discount and sales tax.

Calculate average variable cost per unit from materials, labor and variable overhead, plus contribution margin.