How it works
Enter your current balance, the card's APR (the annual interest rate shown on your statement), and the amount you pay each month. We run the month-by-month amortisation in your browser and show how long until the balance hits zero, the total interest, and the total repaid.
In detail
Credit card interest is usually shown as an APR (Annual Percentage Rate). The card provider charges interest on your outstanding balance, normally every month, so the real cost depends on both the APR and how much you pay back.
Why minimum payments cost so much
If you only make the minimum payment, much of it goes to interest and only a little reduces the balance. A £2,000 balance at 22.9% APR with a £60 monthly payment, for example, takes years to clear and costs hundreds in interest. Paying more each month clears the debt far faster and saves interest.
The maths
- Each month, interest = balance × (APR ÷ 100 ÷ 12).
- New balance = balance + interest − your payment.
- The calculator repeats this until the balance reaches zero.
This is an estimate for guidance. Real cards may add fees, change rates, or charge interest on purchases from the transaction date if you don't pay in full. Always check your statement. The authoritative source is MoneyHelper — Credit cards.
FAQ
How is credit card interest calculated?
Interest is charged on your outstanding balance, usually monthly. Each month's interest is the balance multiplied by the monthly rate (APR divided by 12).
Why does paying only the minimum cost more?
Minimum payments mostly cover interest, so the balance shrinks slowly and you pay interest for longer. Paying more each month clears the debt sooner and saves interest.
Does paying off in full avoid interest?
Usually yes — most UK cards give an interest-free period on purchases if you clear the full statement balance each month. Cash withdrawals are normally charged interest from day one.
What does APR mean?
APR (Annual Percentage Rate) is the yearly cost of borrowing including the interest rate and standard fees, expressed as a percentage. It lets you compare cards.