Debt Repayment Calculator UK

How this debt repayment calculator works

Enter the current outstanding balance on your debt — this might be a credit card, personal loan, car finance or overdraft. Enter the annual interest rate (APR) shown on your statement. If you are on a 0% deal, enter 0. Enter the monthly payment you are making or planning to make.

The calculator shows how many months until the debt is cleared, the total interest you will pay over that period, and the total amount repaid including interest. This gives you a clear picture of what your debt is actually costing you — and how much you could save by increasing your monthly payment.

The impact of paying more

One of the most valuable things this calculator reveals is how dramatically increasing your payment can reduce both time and cost. On a £3,500 debt at 19.9% APR, increasing the monthly payment from £100 to £150 can cut the repayment period by more than a year and save hundreds of pounds in interest. Try different payment amounts to see the difference.

Even a small increase — an extra £20 or £30 per month — makes a meaningful difference on high-interest debt. The key insight is that minimum payments on credit cards are designed to keep you paying interest for as long as possible. Paying more than the minimum is one of the highest-return financial decisions available.

Snowball vs avalanche: choosing your approach

If you have multiple debts, two main strategies exist. The debt avalanche targets the highest interest rate first — mathematically optimal, saves the most money. The debt snowball targets the smallest balance first — psychologically powerful, provides quick wins. Ask Fin's High Impact Debt Reduction tool lets you compare both approaches on your actual debts side by side.

Before committing to any repayment plan, make sure you are meeting minimum payments on all debts to avoid defaults. If you cannot meet minimum payments, contact a free debt advice service — StepChange (0800 138 1111) or National Debtline (0808 808 4000) — before doing anything else.