How to use the loan calculator
- Enter the loan amount, annual interest rate and term in years.
- See your monthly payment and the total interest you'll pay.
How it works
It uses the standard amortizing loan formula, where each monthly payment covers interest first and chips away at the principal. A longer term lowers the monthly payment but increases total interest.
Benefits
- Shows your monthly payment, total interest and total cost from three simple inputs.
- Lets you compare scenarios by changing the rate or term.
- Runs privately in your browser.
- Free and instant.
Limitations to know
- It assumes a fixed rate and equal monthly payments — variable-rate or interest-only loans work differently.
- It does not include fees, insurance, or taxes that a real loan may add.
- It is an estimate for planning, not a formal loan offer.
Common mistakes to avoid
- Entering the annual rate where a monthly rate is expected, or vice versa.
- Comparing loans by monthly payment alone while ignoring the total interest over the term.
- Forgetting that a longer term lowers the payment but raises the total you pay.
Alternatives
For general percentage math use the Percentage Calculator; for sale pricing use the Discount Calculator.
Last updated: August 2026 · Reviewed by the AI Toolbox editorial team.
Frequently asked questions
Does this include taxes or fees?
No — it estimates principal and interest only. Add any fees or insurance separately.
Is it free?
Yes, completely free with no sign-up.