Example result based on the prefilled values.
Monthly
£292.39
Total Cost
£17,034.82
Interest
£2,034.82
Continue your plan
Useful next calculations
Rates & sources
Illustrative fixed-payment loan calculation. It does not model PCP optional final payments, hire-purchase fees or a lender’s personalised APR.
Source: FCA — APR and borrowing-cost guidance — check the linked guidance and any live quote before acting.
When to use this calculator
- When you need a fast estimate before making a bigger decision.
- When you want to compare a few scenarios using the same assumptions.
- When you need a clearer starting point before using a detailed quote or formal document.
- When you want to sanity-check a figure you have seen elsewhere before you rely on it.
- When you are preparing for a conversation with an adviser, supplier, or lender and want to arrive with realistic numbers.
Example: comparing the cost of financing a used car
Use these sample inputs as a quick scenario test, then change one variable at a time to compare outcomes.
Car price
£18,000
Deposit
£3,000
Amount financed
£15,000
APR and term
7.9% over 4 years
The monthly figure matters, but the total interest shows the real cost of stretching the agreement. Test a larger deposit and a shorter term before choosing the offer that only looks cheapest each month.
How to read your results
Monthly
Use this metric to compare scenarios side by side and understand how changes in the key inputs drive the final outcome. If the figure surprises you, isolate one variable at a time and rerun the calculation to identify which assumption is responsible.
Total Cost
This is the headline outcome of the calculation, but it is most useful when read alongside the supporting metrics below it rather than in isolation. Try changing one input at a time and watching how this total moves to understand which driver has the biggest impact.
Interest
Use this metric to compare scenarios side by side and understand how changes in the key inputs drive the final outcome. If the figure surprises you, isolate one variable at a time and rerun the calculation to identify which assumption is responsible.
Method & assumptionsAuthoritative sources
This calculator works out your monthly repayment, total interest paid, and overall cost of borrowing based on the loan amount, interest rate (APR), and repayment term you enter. It uses the standard amortisation formula, so each monthly payment covers accruing interest first with the remainder reducing the outstanding principal. The APR field should reflect the annual percentage rate quoted in your finance agreement — not the flat rate, which can look artificially low. The calculator does not account for arrangement fees added to the loan or payment protection insurance (PPI) premiums, so add those separately if relevant. Results are illustrative; always verify figures with your lender before signing any agreement.
Common mistakes
- !Using optimistic assumptions without testing a more cautious scenario as well.
- !Comparing outputs from different tools without checking that the inputs match.
- !Treating the result as a final quote instead of a planning estimate.
- !Rounding inputs too aggressively, which can produce an output that is noticeably different from your actual situation.
- !Stopping at a single run of the tool rather than adjusting the key variable up and down to understand the range of plausible outcomes.
What to do next
- Compare the same car with a larger deposit and a shorter term, keeping the APR unchanged.
- Check whether the advertised rate is representative APR and add any compulsory fees to the total cost.
- For PCP, request the optional final payment and mileage or condition terms before comparing the agreement with a fully repaid loan.
Frequently asked
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