Simple Interest Calculator
Calculate simple interest with I = P·r·t.
Interest without compounding
Simple interest is principal times rate times time, with no compounding: $1,000 at 5% for three years earns $150. It is common for short-term loans and some bonds.
It is the right model for many short-term personal loans and some bonds, where interest does not compound — useful to compare against a compound offer to see which truly costs less.
Simple vs compound
Over long periods compounding earns far more, so check which your account uses. The figures you enter never leave your device.
Frequently Asked Questions
How does this simple interest calculator work?
It uses the numbers you enter and applies the visible formula or planning rule in your browser.
Is this financial advice?
No. This is an educational estimate for planning. Check important decisions with a qualified financial professional.
Are my numbers uploaded?
No. The calculation runs locally in your browser and nothing is stored by this page.
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