Interest Calculator
Calculate simple or compound interest earned or owed over time.
Switch between simple and compound interest to see how much a balance grows.
ResultUpdates as you type
Enter a positive time period.
Formula
Simple interest
I = P · r · tCompound interest
I = P · ((1 + r)^t − 1)Frequently asked questions
Simple vs compound — what is the difference?
Simple interest is charged only on the original principal. Compound interest is charged on the principal plus previously accumulated interest, so it grows faster.