What does this tool do?
Loan Calculator takes your loan amount, annual interest rate and term, then instantly shows the monthly payment, the total interest you will pay and the total amount repaid. It is built for anyone planning a budget before taking out a mortgage, car loan or personal loan, and for comparing different scenarios side by side.
How to use it
- Enter your values into the fields.
- The result is calculated instantly.
- Read or copy the result.
How the maths works
The tool applies the standard amortization formula used for equal-instalment (annuity) loans: the monthly payment is derived from the principal, the monthly interest rate and the total number of payments. Even though you pay the same amount each month, early payments are mostly interest while later ones go mostly to principal. Total interest is simply the sum of all payments minus the amount you borrowed.
Smart comparison tips
Stretching the term lowers the monthly payment but sharply increases the total interest paid; a shorter term does the opposite. Even a small difference in the rate can mean thousands more over the life of the loan. Remember that fees, insurance and taxes are not part of the basic instalment, so the real cost is higher than the figure shown here.
Frequently asked questions
Should I enter the annual or monthly interest rate?
Enter the annual rate. The tool converts it to a monthly rate internally (dividing by 12) and bases the monthly payment on that.
Why is the total interest so high compared to the loan amount?
Because interest is charged each month on the remaining balance and accumulates over time. The longer the term and the higher the rate, the more total interest you pay.
Do extra payments or a down payment change the result?
Yes. This calculation assumes a fixed term with regular instalments. A down payment lowers the loan amount and extra payments cut remaining interest; re-run it with a reduced principal to see the effect.
Is Loan Calculator free?
Yes. Loan Calculator and all 300+ tools on MagmaNex are completely free with no signup or account required.
Is my data safe?
Yes. Everything runs locally in your browser. The data you enter is never sent to a server, stored, or shared.
Does it work on mobile?
Yes. Loan Calculator works on phones, tablets and desktops — no app download needed.
🔒 Privacy: everything runs in your browser, your data is never sent to a server.