UK Loan Calculator

Enter three numbers — the amount you want to borrow, the annual interest rate, and the term in years — and the calculator returns your monthly repayment, the total interest over the life of the loan, and the total you will pay back. It uses the standard amortising-loan formula: the annual rate is divided by 12 to give a monthly rate, and the fixed payment is set so that after the final month the balance is exactly zero. Each payment is part interest, part principal. Interest is charged on the balance still outstanding, so early payments are interest-heavy, and the split shifts towards principal as the balance falls. The month-by-month schedule under the results shows that split for every payment, and the CSV export drops the whole table into a spreadsheet.

One piece of terminology matters in the UK. Personal loans are regulated consumer credit, and their advertised cost figure is an APR under the Consumer Credit Act regime. The APR folds compounding and any mandatory charges into a single comparable rate, so on a loan with an arrangement fee the APR will sit above the nominal rate the interest is actually charged at. For the payment maths, enter the contractual interest rate from your agreement or quote; use the APR to compare one offer against another, not to compute the repayment.

Take the defaults: £15,000 at 9.9% over 5 years. The monthly rate is 9.9% ÷ 12 = 0.825%. The amortising formula gives a monthly payment of £317.97. Over 60 payments that comes to £19,078, of which £4,078 is interest.

The schedule shows why. In month one, interest is £15,000 × 0.825% = £123.75, so £194.22 of the first £317.97 payment clears principal. After 12 payments the balance is down to £12,560.67, and because interest is only charged on what remains, each payment clears slightly more principal than the one before.

Now shorten the term to 3 years and keep everything else the same. The payment rises to £483.30 — £165.33 more each month — but only 36 payments are made, so total interest falls to £2,399. The shorter term saves £1,679 in interest in exchange for a higher monthly commitment.

The trade-off runs the same way at any rate: interest accrues on the outstanding balance for as long as the balance exists, so anything that shrinks it faster — a shorter term, a lower rate, an overpayment — cuts total interest. The full schedule and its CSV export let you check any month's figures rather than taking the summary on trust.

UK loan adverts that quote a rate must show a representative example, and the rate in it is the representative APR. Under the FCA's rules (CONC 3.5), that is the rate the lender reasonably expects at least 51% of the customers who take the loan through that advert to receive — or better. It is not the average rate, and it is not a rate anyone is guaranteed. Up to 49% of accepted applicants can be offered a higher rate than the one in the advert, typically because of their credit history, income, or the amount and term requested.

That gap is what this calculator is for. Run the numbers at the advertised rate to shortlist loans, then re-run them at the rate on the actual quote before you sign. The difference compounds over the term: on £15,000 over 5 years, an offer at 12.9% instead of a representative 9.9% costs £340.53 a month rather than £317.97 — £22.56 more each month and £1,354 more interest over the loan. A rate that looks close to the advert can still move the total cost by four figures, and the only way to see it is to put your own offer through the same arithmetic.

You do not need the lender's permission to pay a regulated UK personal loan off early. Section 94 of the Consumer Credit Act 1974 gives borrowers a statutory right to repay early, in full or in part, at any time, with a rebate of future interest calculated under the Consumer Credit (Early Settlement) Regulations 2004.

Early settlement is not necessarily free, though. Under those regulations the settlement date used for the rebate is 28 days after the lender receives your notice, and for agreements running longer than 12 months the lender may defer it by one further month — so a lender can in effect charge up to roughly 58 days of additional interest on settlement. On the worked example above, settling after two years — when the schedule shows £9,868.58 still outstanding — roughly 58 days of interest comes to about £155. Separately, for loans taken out since 1 February 2011, repaying more than £8,000 within any 12-month period can attract lender compensation capped at 1% of the amount repaid early (0.5% if less than a year of the agreement remains).

The amortisation schedule gives you the number all of this is computed from: the balance outstanding in any given month. Read the balance off the row for your settlement month and you have the base for the rebate and any interest deferral.

This calculator models a fixed-rate, unsecured personal loan that amortises monthly — the standard shape of a UK bank or online personal loan. Several common products do not fit that shape, and putting their numbers through this page will mislead you.

Secured lending prices differently. Mortgages are typically structured as an introductory deal followed by a reversion rate, and their disclosure figure is the APRC rather than the APR; the UK mortgage calculator (/uk/mortgage-calculator) models that two-stage structure properly.

Credit cards and 0% purchase offers do not amortise like a loan at all. Revolving credit has no fixed term, minimum payments recalculate on the moving balance, and a 0% promotional window changes the arithmetic entirely until it expires.

Variable-rate loans fit the formula only while the rate holds; when it changes, the payment or term is recalculated, so treat any result here as a snapshot at the rate you entered.

Finally, expect penny-level differences from your lender's own schedule. Lenders round the monthly payment and usually adjust the final instalment so the balance closes exactly at zero; this page computes from the unrounded payment, so totals can differ by a few pence. The page also never suggests a rate: market rates move, the rate you get is personal, and the honest input is the one on your own quote.