Loan Calculator

Work out what a loan costs each month and in total

Loan Calculator gives the monthly payment for a loan repaid in equal monthly instalments: a mortgage, a car loan or a personal loan. It also shows the total interest, the total you pay back, how many payments it takes and a full repayment schedule you can download as a spreadsheet.

Add an optional extra monthly payment to see how much sooner the loan is paid off and how much interest that saves. Everything is calculated in your browser and works with any currency.

How to calculate a loan payment

1. Enter the loan amount: the sum you borrow.
2. Enter the annual interest rate as a percentage, such as 6 or 4.75. 0 is allowed.
3. Enter the term in years, months or both, from 1 month to 50 years. 0 years and 36 months is the same as 3 years.
4. Optionally enter an extra amount you’d pay on top each month, and the month of the first payment if you want dates on the schedule.
5. Read the monthly payment and totals, then switch between the monthly schedule and the yearly summary, or click Download CSV.

What each figure means

• Monthly payment: the regular payment, rounded to the cent. For 200,000 at 6% over 30 years it’s 1,199.10.
• Total interest: the interest added up over every payment.
• Total paid: the loan amount plus the total interest, extra payments included.
• Number of payments: how many monthly payments it takes, with the time in years and months. With a first payment month, the month of the last payment is shown too.
• Final payment: because the payment is rounded to the cent, the last one is adjusted so the balance ends at exactly 0. It is usually within a few cents of the others; the tool says so whenever it differs.
• Schedule: each payment split into principal, interest and any extra, with the balance left. The yearly summary adds up each block of 12 payments.

When a loan calculator helps

• Comparing offers: see what a different rate or term does to the monthly payment and to the total cost.
• Overpaying: decide whether a regular extra payment is worth it.
• Saving instead: compare the interest you’d pay with what the same money could earn, using the Compound Interest Calculator.

Limits to keep in mind

• Payments are monthly and the rate is fixed for the whole term; variable rates, payment holidays and interest-only periods aren’t modelled.
• With a small amount over a long term, rounding to the cent can make the last payment noticeably different from the others. The tool points this out when it happens.
• Lenders may round differently or count interest by days, so their figures can differ slightly. This is an estimate, not financial advice.

The maths behind a repayment schedule

The payment formula

The payment is P × r ÷ (1 − (1 + r)^−n), where P is the loan amount, r the monthly rate and n the number of payments. The annual rate is treated as a nominal rate compounded monthly, so r is the annual rate divided by 12 — 6% a year is 0.5% a month. That’s how most mortgages and personal loans quote their rate. At 0% the payment is simply the amount divided by the number of payments.

Each month, interest is the balance × r, rounded to the cent, and the rest of the payment repays the loan — so early payments are mostly interest.

Interest rate vs APR

The rate entered here is the interest rate alone. An APR (annual percentage rate) also folds in arrangement fees and some other charges, so it’s usually a little higher. Use the APR to compare offers, but enter the loan’s own interest rate here to reproduce its payment.

Why extra payments save interest

An extra payment goes straight to the balance, and every later month’s interest is worked out on that smaller balance. The saving compounds: paying 200 extra a month on 200,000 at 6% over 30 years clears the loan in 21 years and saves 79,800.86 in interest. Check whether your lender charges for overpaying before you plan on it.

Loan Calculator: common questions