InstalmentLoans

Car Finance Calculator

A car finance calculator estimates the monthly repayment, total interest and amount financed on a vehicle. Enter the cash price, deposit, part exchange value, any admin fee, representative APR and term.

By the InstalmentLoans Editorial Team · Last updated 2 October 2026

Get an instalment loan quote Check the repayment first

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WARNING: Late repayment can cause you serious money problems. For help, go to moneyhelper.org.uk

Enter your numbers and press Calculate. Nothing you type leaves your browser.

How this calculator works

Car finance is secured by the vehicle. The amount financed is the cash price plus any admin fee, minus your deposit and the part exchange value.

Amount financed = cash price + fee - deposit - part exchange.

Then M = P * r * (1 + r)^n / ((1 + r)^n - 1).

If the deposit and part exchange cover the price and fee, nothing is financed and the repayment is zero.

The cash price should include VAT. This models a fixed-rate repayment plan; hire purchase and PCP deals can differ, so use the figures from your own quote.

Frequently asked questions

What is included in the amount financed?
The cash price plus any admin or arrangement fee, minus your deposit and the value of your part exchange. Interest is then charged on that amount.
Is this the same as PCP or hire purchase?
Not exactly. This models a fixed-rate repayment plan. PCP deals include a balloon payment and mileage limits, while hire purchase can have different fee structures.
What deposit should I enter?
Enter the cash amount you will pay up front, plus the value the dealer has agreed for your current car as a part exchange.
How does the term affect the cost?
A longer term lowers the monthly repayment but increases the total interest, and can keep you in negative equity for longer. Compare the total amount payable, not just the monthly figure.

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