Simple Interest Calculator
Simple Interest Calculator
I = P × R × T
What is the Simple Interest Calculator?
Simple Interest Calculator calculate simple interest: i = p × r × t. It is part of Home of Calculators's Finance Calculators suite for financial planning, loan calculations, investment analysis. The calculator is designed for investors, homebuyers, business owners, but anyone can use it. No signup, no ads, no tracking. Just accurate math, computed locally in your browser using a BigNumber-precision math engine.
Simple interest is calculated only on the principal amount. Unlike compound interest, it does not earn interest on previously accumulated interest. It is commonly used for short-term loans and some bonds.
PPrincipal ($)rAnnual rate (%)tTime (yr)How to use the Simple Interest Calculator
- 1
Convert rate to decimal
Divide the annual interest rate by 100 to get the decimal form.
- 2
Multiply the three values
Calculate I = P × r × t using the decimal rate.
- 3
Add principal for total
The total amount to repay is P + I.
Quick tips
- All calculations run locally in your browser; your data never leaves your device.
- For best results on mobile, rotate to landscape when entering many values.
- Bookmark this page to come back to your calculation anytime.
- Need a different calculator? Try our visual builder to create your own.
Why Home of Calculators
- 100% private (calculations run in your browser)
- 128-bit BigNumber precision (no rounding errors)
- Works on any device: phone, tablet, desktop
- Free forever (no signup, no ads, no upsells)
Frequently asked questions
Is the Simple Interest accurate?
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Yes. Home of Calculators uses a BigNumber-precision math engine (64-128 decimal digits) to ensure calculations are accurate. We run 96+ automated tests covering unit conversion, financial formulas, health formulas, and more. For critical decisions (financial, medical, legal), we still recommend consulting a qualified professional.
Is the Simple Interest Calculator free?
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Yes. Every calculator on Home of Calculators is 100% free, with no signup, no ads, and no hidden fees. The entire platform is free forever.
Do you store the values I enter?
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No. All calculations happen in your browser. We never see, store, or transmit your inputs to any server. Your data stays on your device.
Can I use the Simple Interest on my phone?
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Yes. Home of Calculators is fully responsive and works on any device (phone, tablet, laptop, or desktop). The interface adapts to your screen size.
Can I embed this calculator on my own website?
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Yes. Click the "Share" button to get an iframe embed code. The embedded calculator will look like any other Home of Calculators widget. You can also build a fully customized version using our visual builder.
Can I build my own custom calculator?
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Absolutely. Home of Calculators's visual builder lets you add fields, write formulas, choose a theme, and brand the result with your own logo, all without writing code.