The UK Personal Loan Calculator shows exactly what a personal loan will cost you each month and over its full life. Borrowing £5,000 over three years feels very different at 4% APR than at 14% — and a longer term that lowers your monthly payment can quietly add hundreds of pounds of interest. This tool uses correct amortisation maths to give you the fixed monthly repayment, the total interest, the total amount repayable, and a complete month-by-month schedule.
How it works
A personal loan is an amortising loan: you make a fixed monthly payment that covers interest on the outstanding balance plus a slice of principal, with the principal share growing each month. The payment is given by the annuity formula:
monthly_payment = P × i / (1 − (1 + i)^(−n))where P is the amount borrowed, i is the monthly rate (APR ÷ 12), and n is the number of monthly payments. Early payments are mostly interest; later ones are mostly principal. Total interest is simply monthly_payment × n − P.
Example
Borrow £10,000 at 6.9% APR over 5 years (60 months):
- Monthly rate
i = 0.069 / 12 ≈ 0.00575. - Monthly payment works out to roughly £197.
- Total repayable ≈ £11,850, so total interest ≈ £1,850.
Stretch the same loan to 7 years and the monthly payment falls, but total interest rises noticeably — the headline trade-off the tool makes visible.
Notes
The result models interest only — arrangement fees, optional insurance, and missed-payment charges are excluded. Always check the lender’s representative example and total amount repayable. Everything is calculated in your browser and nothing is uploaded.