UK Loan Repayment Calculator

Whether you are borrowing for a car, home improvements, or to consolidate other debts, the loan amount and interest rate only tell you part of the story. What actually matters day to day is your monthly repayment, and over the full term, how much interest you end up paying on top of what you borrowed.

This calculator turns a loan offer into clear numbers you can compare against your budget, and shows exactly how your first year of payments breaks down between interest and paying off the amount you borrowed. It works for any fixed rate personal loan, whether you are comparing offers from your bank, a building society, or an online lender.

How to use the loan repayment calculator

Enter the amount you want to borrow, the annual interest rate you have been offered or expect, the term in years, and a start date. The calculator instantly shows your monthly repayment, total interest, total amount repaid, and your exact payoff date, along with a month by month breakdown for the first year.

How the repayment is calculated

UK personal loans typically use a standard amortising repayment structure, the same style used for mortgages. Every month you pay the same fixed amount, but the mix changes over time: early payments are mostly interest, since the balance is at its highest, while later payments are mostly capital, since less interest builds up on a shrinking balance. By the end of the term, the balance reaches exactly zero.

This is different from an interest only arrangement, where you would pay just the interest each month and still owe the full amount at the end. Almost all personal loans in the UK are repayment loans rather than interest only, which is why your balance steadily falls to zero rather than staying the same throughout the term.

Worked example

Say you borrow £10,000 at an APR of 8% over 5 years. Your monthly repayment works out at around £202.76. Over the full 5 years, or 60 monthly payments, you would repay a total of around £12,165, meaning £2,166 of that is interest on top of your original £10,000.

Now compare a shorter term. The same £10,000 loan over 3 years instead of 5 pushes the monthly repayment up to around £313, but the total interest paid drops to roughly £1,281, about £885 less than the 5 year option. Spreading a loan over a longer term always reduces your monthly payment, but it always increases the total interest you pay, since the lender is charging interest for longer.

Looking at the first 12 months of the 5 year loan specifically, roughly £739 of your first year's payments go towards interest, with the remaining £1,694 or so reducing the capital balance. By the final year, that split flips almost entirely the other way, with barely any interest left to pay and most of each payment clearing the remaining capital. This is exactly the kind of detail the first 12 months schedule in the results shows you month by month.

Common mistakes to avoid

A common mistake is focusing only on the monthly repayment figure without checking the total cost of the loan. A longer term can make a big purchase feel more affordable month to month, but it often costs considerably more overall once all the extra interest is added up. It is worth comparing at least two or three term lengths before committing.

Another mistake is not shopping around. Lenders price loans differently based on your credit history and the amount you want to borrow, and the APR you are offered can vary a fair amount between providers for what looks like the same loan on paper. Getting a few quotes, using soft search tools where available so your credit file is not affected, is usually worth the extra few minutes.

It is also worth being careful about the difference between the interest rate you are quoted and the representative APR advertised by a lender. UK rules mean the representative APR only has to be offered to at least 51% of successful applicants, so depending on your credit history, the rate you are actually offered once you apply can be higher than the headline figure you first saw advertised. Always base your final decision on the exact rate in your loan offer, not the advertised representative example.

Finally, watch out for payment protection insurance or other add ons offered alongside the loan. These can increase your monthly cost noticeably, and are entirely optional in almost all cases. Work out whether you actually need the cover on its own merits, rather than because it was bundled into the application process.

Related calculators

If you are weighing up a loan against a credit card, our credit card payoff calculator shows the same kind of breakdown for revolving credit. If the loan is for anything property related, our mortgage calculator uses the same repayment maths on a larger scale. Before taking on any new borrowing, it is worth checking your take-home pay to make sure the repayment comfortably fits your monthly budget, and our income tax guide if you want the fuller picture of what you actually have available to spend each month.