APR Interest Cost Calculator UK
This APR cost calculator helps you work out the true cost of borrowing in the UK. Instead of looking only at the interest rate, it shows how APR, arrangement fees, monthly charges and loan term combine to affect your monthly payment and total amount repaid.
It is useful if you are comparing personal loans, car finance, home improvement finance or other credit products where the headline monthly payment does not tell the full story.
What this calculator includes
- Amount borrowed
- APR percentage
- Loan term in years and months
- Arrangement fee
- Monthly fee
- Fee treatment, including whether an upfront fee is added to the loan
- Estimated monthly repayment
- Total interest, total fees and total borrowing cost
How it works
The calculator uses the amount borrowed, APR and repayment term to estimate your monthly repayment. It then separates the overall cost into interest and fees so you can see exactly what you are paying for the credit.
If an arrangement fee is added to the loan, the fee becomes part of the financed balance. That means you may also pay interest on the fee over the term, which increases the total borrowing cost.
Example calculation
Suppose you borrow £10,000 over 3 years at 9.9% APR with no monthly fee and no upfront arrangement fee. Your monthly payment may look manageable, but the total repaid will still be materially higher than £10,000 because of interest.
If you then compare the same loan over 5 years instead of 3, the monthly payment usually falls, but the total interest paid often rises. That is why checking total borrowing cost matters, not just the monthly figure.
Why your results may vary
- The representative APR advertised may not be the rate you are personally offered
- Some lenders calculate charges differently or include extra product-specific fees
- Real agreements may include early repayment terms, late fees or promotional conditions
- The exact repayment schedule can differ slightly depending on lender rounding and timing
Who this calculator is for
- Anyone comparing personal loan offers
- Borrowers checking whether fees materially change the cost of finance
- People deciding between a shorter or longer loan term
- Users who want to see the full borrowing cost before applying
Important note
This APR cost calculator gives an estimate only. Actual loan costs depend on the lender, your credit profile, the rate you are offered, and the exact terms of the agreement. Always review the lender's pre-contract information before taking out credit.
Use the calculator above to estimate your monthly repayments and compare the total cost of borrowing across different APRs, fees and loan terms.