Interest Rate Calculator
NewFind the implied interest rate from any loan or investment given the principal, interest amount, and time period. This reverse calculation is useful when evaluating financial products that advertise in terms other than APR, or when analyzing historical investment returns. Enter the principal amount, total interest paid or earned, and the time period to see the annual interest rate.
Interest Rate Calculator
Find the implied interest rate given principal, interest amount, and time period.
Implied Rate
4.77%
compound interest
Total Amount
$11,500.00
Interest Earned
$1,500.00
Interest / Principal
15%
How to Use Interest Rate Calculator
- 1Enter principal amount
- 2Enter total interest paid or earned
- 3Set time period in months or years
- 4View the implied annual interest rate
Your Privacy is Protected
Interest Rate Calculator runs entirely in your browser. Your files and data are never uploaded to any server, never stored, and never shared. Everything happens locally on your device using secure browser APIs.
Frequently Asked Questions
What is APR vs interest rate?
The interest rate is the base borrowing cost. APR (Annual Percentage Rate) includes fees and other charges, making it a more complete measure of loan cost.
How do I find the rate on an existing loan?
You need the original principal, total interest paid (or total payments minus principal), and loan term. Enter these values to calculate the implied rate.
Why Use This Tool?
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