Interest Rate Calculator
Work backward from your starting amount and ending balance to find the annual interest rate that got you there.
Solving for the interest rate
Sometimes you know how much money you started with and how much it grew to, but not the rate that got you there. This calculator solves for that missing annual interest rate using either the simple interest formula or the compound interest formula, depending on which applies to your situation.
How this calculator works
For simple interest, the rate is found using Rate = (Ending Amount − Starting Amount) / (Starting Amount × Years). For compound interest (compounded annually), the rate is found using Rate = (Ending Amount / Starting Amount)^(1/Years) − 1. Enter your starting amount, ending amount, the number of years between them, and choose which interest type applies.
This calculator is for general educational and planning purposes. If your real account compounds more often than annually (such as monthly or daily), the effective rate may differ slightly from this estimate.