Loan Calculator

How to use the Loan Calculator

1. Enter the loan amount you want to borrow.
2. Enter the annual interest rate as a percentage (use 0 for an interest-free loan).
3. Enter the loan term and choose Years or Months.
4. Press Calculate (or the Enter key) to see your monthly payment, total payments, total interest and total amount paid.
5. Use Reset to clear the fields, or Copy result to copy the figures.

What a loan calculator does

A loan calculator estimates what a fixed-rate loan will cost you. From three simple inputs — how much you borrow, the interest rate, and how long you take to repay — it works out your regular monthly payment and shows how much of your money goes toward interest over the life of the loan. It is useful for mortgages, car loans, personal loans and any other loan repaid in equal monthly instalments.

How the calculation works

This tool models a standard amortizing loan, where you pay the same amount every month and each payment covers the interest due plus a slice of the balance until the loan reaches zero. It uses these formulas:

• Monthly payment (interest > 0) M = P · r · (1+r)ⁿ ÷ ((1+r)ⁿ − 1)
• Monthly payment (0% interest) M = P ÷ n
• Total amount paid M × n
• Total interest (M × n) − P

Here P is the loan amount, r is the monthly interest rate (the annual rate divided by 12 and by 100), and n is the number of monthly payments. Intermediate values are kept at full precision and only the displayed figures are rounded to two decimal places.

Monthly payment

The monthly payment is the fixed amount you pay each month. Early on, more of it goes toward interest; later, more goes toward the balance. A lower rate or a longer term reduces the monthly payment, while a shorter term raises it but usually costs less interest overall.

Total interest

Total interest is the extra you pay for borrowing — everything beyond the original amount. It is the total amount paid minus the loan amount. Stretching a loan over more months lowers the monthly payment but generally increases the total interest.

Total amount paid

Total amount paid is your monthly payment multiplied by the number of payments — the full cost of the loan including interest. Comparing this figure across different terms or rates is a quick way to see the true cost of borrowing.

Example

Borrow 10,000 at 5% annual interest over 3 years (36 months). The monthly payment works out to about 299.71, the total amount paid is about 10,789.52, and the total interest is about 789.52. Change the rate to 0% over 2 years and the monthly payment becomes exactly 416.67 with no interest at all.

Important limitations

This calculator estimates principal and interest only. It does not include fees, taxes, insurance, or lender-specific rules, and it assumes a fixed rate with equal monthly payments and standard monthly compounding. Real loan offers can differ, so treat the results as a guide and confirm the exact figures with your lender before making a decision. This tool is not financial advice.

Is it private?

Yes. The Loan Calculator runs entirely in your web browser using JavaScript. The numbers you enter are never sent to a server, never stored, and never shared. There is no sign-up and no tracking.