💵Simple Interest Calculator
Interest and total from P, rate & time.
Disclaimer: These tools provide estimates for general information and educational use only. They are not financial, investment, tax or legal advice. Results can differ from your bank or provider's actual figures — please verify important decisions with a qualified financial professional.
About the Simple Interest Calculator
Calculate simple interest and the total amount from principal, annual interest rate and time period. Uses the formula SI = (P × R × T) ÷ 100. Free online simple interest calculator.
How to use the Simple Interest Calculator
- 1Enter your numbers into the Simple Interest Calculator fields above.
- 2Adjust the rate, period, units or other options to match your situation.
- 3Your result is calculated instantly as you type — there's no submit button.
- 4Nothing is stored or uploaded; every calculation runs privately in your browser.
Why use this tool?
Private by design
The Simple Interest Calculator runs entirely in your browser — nothing you enter is uploaded to a server.
Free, no signup
Use it as much as you like. There's no account, no paywall and no watermark.
Fast & instant
Results appear the moment you type or click — no waiting, no page reloads.
Works anywhere
Any device or browser, even offline once the page has loaded.
Frequently asked questions
What is the simple interest formula?＋
Simple Interest = (Principal × Rate × Time) ÷ 100, where rate is per year and time is in years.
How is it different from compound interest?＋
Simple interest is calculated only on the original principal, while compound interest is calculated on the principal plus accumulated interest.