Debt Repayment Calculator
See how long a debt will take to clear, how much interest it will cost, and what paying a little extra each month could save.
Enter the balance, interest rate and what you pay each month. Results update instantly and are calculated in your browser.
Your repayment plan
Balance over time
How the outstanding balance falls month by month with and without the extra payment.
Repayment schedule
Month-by-month, including interest and the final partial payment.
| Payment | Month | Balance at start | Interest | Payment | Balance at end |
|---|
How the repayment calculation works
Each month, interest is added to the outstanding balance and then your payment is taken off. The calculation is done in pennies: each month’s interest is rounded to the nearest penny, and the last payment is only what’s left rather than a full instalment — so the totals add up exactly.
APR or monthly rate?
UK lenders show an APR (annual percentage rate), which reflects interest compounding over a year. The matching monthly rate is the one that compounds back to it: (1 + APR)1/12 − 1, which for 22.9% APR is about 1.73% a month. Some agreements quote a yearly interest rate that’s simply divided by 12 each month — if yours says so, choose that option and 22.9% becomes 1.91% a month.
When the payment is too small
If your monthly payment doesn’t cover the interest added each month, the balance never falls. Instead of producing an endless schedule, the calculator shows the first month’s interest and the payments that would clear the debt over a range of timescales. It also stops at 50 years if a payment is only just above the interest.
What this calculator assumes
- The interest rate stays the same and you pay the same amount every month, with no missed payments and no new borrowing.
- No fees or charges are added. Credit card promotional rates aren’t modelled — a 0% deal can be entered as 0%, but only for its length.
- Lenders calculate interest in different ways, often daily and on statement dates, so your actual interest may differ a little.
- Credit card minimum payments usually fall as the balance falls. This calculator keeps your payment fixed, which is what makes a fixed payment so much faster than paying only the minimum.
If you have several debts, the Debt Snowball vs Avalanche Calculator compares two ways of prioritising them.
Sources
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MoneyHelper
Free, impartial money and debt guidance backed by the UK government, including help finding free debt advice.
Frequently asked questions
What is the difference between APR and the interest rate?
APR is the annual percentage rate: it reflects interest compounding over a year and, on most credit agreements, compulsory fees. A nominal yearly rate charged monthly is simply divided by 12 each month. For the same number, the APR option gives a slightly lower monthly rate.
Why is my statement interest different from this calculator?
Lenders often charge interest daily and on statement dates that don’t line up with calendar months, and may treat different types of spending at different rates. This calculator uses a constant monthly rate, so treat it as an estimate.
What happens if I only make the minimum payment?
Credit card minimum payments are usually a small percentage of the balance, so they shrink as the balance falls and the debt takes much longer to clear. Paying a fixed amount — even one equal to today’s minimum — clears it considerably faster.
Is it worth paying extra each month?
Extra payments reduce the balance that interest is charged on, so they save interest and shorten the term, as the comparison shows. Some loans charge a fee for repaying early, so check your agreement first.
Where can I get help with debt?
If you are struggling with repayments, free and confidential debt advice is available. MoneyHelper, which is backed by the government, can help you find a free debt advice service.