Personal Loans and APR Explained: How to Compare the Real Cost
Confused by personal loan APR? This plain-English guide explains what APR really means, how representative APR works,…
This car finance calculator turns a car's price, your deposit and the APR into the numbers that actually matter: the monthly payment, the total interest, and how much you'll have repaid by the end of the deal. It works for both PCP and HP agreements, so you can see the real cost before you sit in a dealer's office.
It's built for anyone weighing up a new or used car in the UK - first-time buyers, families upgrading, and people deciding whether finance or a personal loan makes more sense. Adjust the figures to compare deals and understand exactly what you'll pay each month.
Monthly payment
on a loan over years
Overpaying saves you
interest saved
sooner
Estimate only. Representative APR and actual offers depend on your credit profile.
| Year | Interest | Principal | Balance left |
|---|---|---|---|
| Scenario | Monthly | Total interest | Total repaid | Term | |
|---|---|---|---|---|---|
Enter the car's cash price, your deposit (including any part-exchange value), the APR the lender has quoted, and the length of the agreement in months. If it's a PCP deal, add the balloon payment - the lump sum due at the end. The car finance calculator returns your estimated monthly payment, the total interest you'll pay, and the total amount repayable.
The two main ways to finance a car in the UK are Personal Contract Purchase (PCP) and Hire Purchase (HP). They sound similar and both spread the cost over monthly payments, but they behave very differently - and that difference is the whole reason a vehicle-specific calculator beats a plain loan tool.
Hire Purchase (HP) is the straightforward one. You pay a deposit, then equal monthly payments that clear the entire balance plus interest. When the last payment lands, the car is yours. There's no lump sum at the end and nothing left to decide.
Personal Contract Purchase (PCP) defers a big slice of the car's value to the end of the term. That deferred amount is the balloon payment, also called the Guaranteed Future Value or optional final payment. Because you're only financing the difference between the price and that balloon (plus interest on the whole amount), your monthly payments are lower than the equivalent HP deal. At the end you choose one of three things: pay the balloon and keep the car, hand the car back and walk away, or use any equity above the balloon as a deposit on your next car.
Lower monthly payments make PCP look cheaper. They aren't - you're paying interest on the balloon for the whole term and you still don't own the car until you settle it. That's exactly the trap this car finance calculator is meant to expose.
From a few inputs, the tool gives you the figures a dealer's brochure tends to bury:
Seeing the total payable next to the cash price is the moment most people pause. A tempting monthly figure can hide thousands of pounds of interest once you total it up over four or five years.
Car finance is a reducing-balance loan, so the maths is the same engine behind a mortgage or personal loan. Interest is charged on the outstanding balance, the balance falls as you pay, and the monthly figure is set so the loan clears over the agreed term (with PCP, it clears down to the balloon rather than to zero).
In plain words:
The monthly payment itself comes from the standard amortising-loan formula. Using r as the monthly interest rate (the annual rate divided by 12) and n as the number of months, the payment on a balance P with no balloon is:
payment = P × r ÷ (1 − (1 + r)−n)
When there's a balloon B, the present value of that balloon is subtracted from the amount the monthly payments need to cover, which is why PCP payments are lower. APR matters here too: the advertised APR includes most compulsory fees, so it's a fairer comparison between deals than a headline "flat rate". Always compare APRs, not monthly prices.
Take Priya, who's buying a two-year-old estate to fit the kids and the dog. The cash price is £18,000. She puts down a £2,000 deposit, the dealer quotes 9.9% APR, the term is 48 months, and the balloon (final) payment is £6,500.
Now compare the same car on HP - no balloon, so the monthly payments clear the full £16,000 plus interest. The monthly figure jumps to around £405, but Priya owns the car outright after the final payment with nothing left to settle. PCP feels lighter month to month; HP is usually cheaper overall and ends with you actually owning the car. The right choice depends on whether she wants to keep the car or swap it every few years.
Tom is buying his first new car at £24,000 on Hire Purchase. He pays a £3,000 deposit, the APR is 7.9%, and the term is 60 months with no balloon.
Stretching the term from 48 to 60 months drops the monthly payment but adds interest, because you owe the money for longer. That trade-off - lower monthly versus higher total - is the single most useful thing to test in the calculator before you sign.
The balloon is the part of PCP that catches people out. It's set at the start based on the car's predicted value at the end of the agreement (the Guaranteed Future Value). Three points worth holding onto:
Your deposit can be cash, the value of a car you're trading in, a dealer contribution, or a mix. A bigger deposit cuts the amount financed, which lowers both the monthly payment and the total interest. If you're part-exchanging, get the trade-in value confirmed in writing and treat it as deposit in the calculator. Be wary of a generous part-exchange figure paired with a high APR - the headline can give on one hand and take on the other.
You're allowed to settle regulated car finance early. Under the Consumer Credit Act you can ask the lender for a settlement figure, and there's usually a rebate of some future interest, so the figure is less than simply adding up the remaining payments. Some agreements apply a small early-settlement interest charge (commonly up to about one to two months' interest), so always request the exact figure rather than estimating. If you're tempted to clear it with savings or another loan, run the numbers in an early repayment calculator first to check the saving is real after any charge.
A few errors come up again and again with UK car buyers:
There's no single right answer. PCP suits people who want a newer car every three or four years and lower monthly payments, and who are comfortable not owning the car unless they pay the balloon. HP suits people who want to own the car at the end and don't mind paying more each month to get there. A personal loan can beat both if your credit is good and you want full ownership and no mileage limits from the start. The honest move is to price all three and compare the total cost of borrowing, not the monthly headline. For a general view of any fixed repayment, a loan calculator shows the same amortising maths applied to any borrowing.
For impartial, non-commercial guidance on the different agreement types, the Money and Pensions Service runs a clear explainer at MoneyHelper.
These figures are estimates for guidance only and are not personal financial advice. Your actual rate, payments and settlement figure depend on the lender's offer and a credit check - always read the agreement before you sign.
This is for vehicle borrowing specifically — a Hire Purchase agreement or a personal loan used to buy a car. It shows the monthly payment and, importantly, the total interest across the term, which is the figure dealerships present least clearly.
It does not model PCP, and that distinction matters. A Personal Contract Purchase has a large optional final payment based on the car’s predicted future value, so the monthly figure looks far lower than HP for the same car while you own nothing until you pay the balloon. Comparing a PCP monthly payment against an HP monthly payment is not a like-for-like comparison.
Pricing a car is rarely just the finance. These tools help with the rest of the decision:
Insurance is a big running cost too: the car's insurance group (1 to 50) has a major effect on your premium.
Monthly repayments and the total cost of borrowing £10,000 at typical UK personal loan APRs. Scale to your amount.
| APR | Monthly (3 years) | Monthly (5 years) | Total interest (5y) |
|---|---|---|---|
| 6% APR | £304 | £193 | £1,600 |
| 9% APR | £318 | £208 | £2,455 |
| 12% APR | £332 | £222 | £3,347 |
| 19% APR | £367 | £259 | £5,564 |
| 29% APR | £419 | £317 | £9,045 |
Lenders must show the APR including fees. Free debt and borrowing guidance: MoneyHelper.
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