Finance & Money
Rates & guidance reviewed
Before you sign a personal loan or car finance agreement, knowing the monthly payment and total interest helps you compare offers on a like-for-like basis. This free UK loan repayment calculator estimates fixed monthly repayments, total interest and total repayable from the amount you borrow, the annual rate and the term.
It uses the standard capital-and-interest amortisation formula (the same family of maths as most unsecured personal loans and many hire-purchase style car deals). Add an optional extra amount each month to see how many months you save and how much interest you cut. Everything runs in your browser — we do not store the numbers you enter or send them to a server.
Try the worked examples below (for example £8,000 car finance at 7.9% over 4 years, or £10,000 at 8.9% over 4 years with an extra £50 a month), then plug in your own quote. Arrangement fees, optional insurance, balloon payments, early repayment charges and variable rates are not included — always read the pre-contract credit information from the lender.
Prefer the written walkthrough? Start with How UK credit card interest and payoff time are calculated or How UK fuel cost is calculated from miles, MPG and the pump price. Guides match the figures on this page.
Fixed-rate amortising loan model · not a broker quote
Use the quoted annual rate
e.g. 3, 4 or 5 — use 1.5 for 18 months
0 = scheduled payment only
Guidance only — not a credit offer. Arrangement fees, payment protection, balloon payments, variable rates, early repayment charges and overpayment limits are not included. For home loans use the UK Mortgage Calculator.
Static sample calculations you can read without using the form. Figures match this tool's maths — always re-run with your own numbers for a personal estimate.
Typical mid-size car finance style repayment — matches the calculator’s car example preset.
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Assumes a fixed rate and level monthly payments that clear the balance. Not a PCP balloon product.
Common unsecured personal loan size for home improvements, debt consolidation or a large purchase.
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Default starting scenario in the calculator — useful mid-size benchmark.
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0% promotional or interest-free credit — principal split evenly across the term.
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Missing a payment on a 0% deal can still incur charges or end the promotional rate — check the agreement.
Same default loan as the scheduled example, with the extra-payment preset — months saved and interest saved versus sticking to the schedule.
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Early repayment charges and overpayment limits are not modelled. Last payment may be smaller than £298.38.
Same car-finance example with an extra £50 on top of the £194.93 scheduled payment.
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Larger unsecured loan — extra £100 a month versus the £317.97 scheduled payment.
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For a fixed-rate capital-and-interest loan, lenders use a standard amortisation formula. With loan amount P, monthly interest rate r (annual rate ÷ 12), and n months (years × 12), the monthly payment is M = P × [r(1+r)^n] ÷ [(1+r)^n − 1]. If the rate is 0%, the payment is simply P ÷ n.
Example: £8,000 at 7.9% over 4 years has r = 0.079 ÷ 12 and n = 48, giving about £194.93 per month in this tool, with roughly £1,357 total interest. A longer term lowers the monthly figure but usually raises total interest — compare 3 vs 5 years before you sign.
This models level monthly payments that clear the balance at the end of the term. It is not a full regulated APRC illustration and does not replace the lender’s pre-contract credit information.
The scheduled monthly payment M is the amount that would clear the loan in exactly the term you entered. Extra per month is added on top: each month you pay M + extra (the last month may be smaller). Interest is charged on the remaining balance at APR ÷ 12. Paying extra cuts the balance faster, so you finish in fewer months and pay less interest.
Worked example: £10,000 at 8.9% over 4 years is about £248.38 a month and £1,922.04 interest if you stick to the schedule. An extra £50 a month (£298.38) clears it in 39 months and cuts interest to about £1,539.66 — 9 months and £382.38 saved. An extra £100 a month finishes in 33 months and saves about £635.42.
Early repayment charges, overpayment limits, daily interest and variable SVR are not modelled. Some lenders cap how much you can overpay each year, or charge for settling early. This is not a settlement-figure quote — check the agreement.
Unsecured personal loans and many hire-purchase style car deals use fixed monthly repayments over a set term — the same family of maths as this tool. PCP and some car products add a large optional final (balloon) payment; those need the lender’s schedule rather than a simple amortising model.
Mortgages are also amortising but involve much longer terms, loan-to-value bands and product fees. Use our dedicated UK Mortgage Calculator for home loans. Credit cards are revolving debt — use the Credit Card Payoff Calculator if you are clearing a card balance rather than a fixed loan.
UK student loans are different: you repay a percentage of income above a plan threshold, not a fixed instalment that clears the balance on a set date. If that is what you need, use the UK Student Loan Calculator (Plan 1, 2, 4, 5 and postgraduate) instead of this page.
Lenders publish a representative APR that can include certain fees annualised under regulated rules. This calculator treats the percentage you type as a simple annual interest rate compounded monthly for repayment estimates — useful for comparing rates on a like-for-like monthly payment basis.
If an arrangement fee is added to the loan, include it in the loan amount above. If you pay a fee upfront, add it to the total cost manually when comparing “total amount payable” on different quotes.
Look beyond the headline monthly payment. A longer term can make a loan feel cheaper each month while costing hundreds more in interest. Compare total repayable and total interest for the same loan amount across rates and terms.
Check early settlement terms, late payment charges and whether payment protection is optional. Affordability still depends on your income and other outgoings — pair this tool with our take-home pay calculator if you are budgeting a new monthly commitment.
Always confirm rates, bands and eligibility on official pages. Our tools are simplified estimators for guidance only.