How to Calculate a Loan Payment

By Daniel · Updated July 2026

A loan payment is worked out so that a fixed amount each month clears the debt exactly by the end of the term, while covering the interest along the way. Three numbers drive it: how much you borrow, the interest rate, and how long you take to repay.

What each number does

  • The amount is what you borrow. A bigger loan means a bigger payment, in proportion.
  • The interest rate is the yearly cost of borrowing. Even a small change moves the payment and, more sharply, the total interest.
  • The term is how long you take. A longer term lowers each monthly payment but means more payments — so you usually pay more interest overall.

How to calculate it

  1. Open the loan calculator and enter the amount, the annual interest rate and the term.
  2. It shows your regular payment.
  3. Look at the total interest too — that is the real price of the loan, on top of what you borrowed.

The trap with longer terms

Stretching a loan over more years is tempting because the monthly payment drops. But you are paying interest for longer, so the total cost climbs — sometimes a lot. Try a couple of terms side by side and compare the total interest, not just the monthly figure, before you decide.

This is a general calculation to help you compare options. Real quotes can include fees and different compounding, and this is not financial advice — check the exact figures with the lender.

Loan Calculator
Enter the amount, rate and term to see your monthly payment and total interest. Runs in your browser.
Open the tool →

Common questions

How is a monthly loan payment calculated?

From the amount borrowed, the interest rate and the term, using the standard amortisation formula so a fixed payment clears the loan by the end.

Does a longer loan cost more?

Usually yes. A longer term lowers each payment but adds more payments and more interest, so the total cost is higher.

What is total interest?

It is everything you pay on top of the amount borrowed — the true price of the loan, and the best number for comparing options.

Is this financial advice?

No. It is a calculator to help you compare scenarios. Confirm exact terms, fees and rates with the lender before committing.

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