calcbase.

Credit card payoff calculator

See how long your balance takes to clear at the payment you are making, and what paying a little more each month would change.

Your details
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Set this above zero to see what paying more would save.

How this is calculated

Interest is charged monthly on the balance at one twelfth of the APR. Your payment covers that interest first, and only the remainder reduces what you owe.

If the payment is smaller than the monthly interest, the balance grows no matter how long you keep paying. The calculator says so rather than returning a number.

A fixed payment is assumed throughout. A card issuer minimum payment is normally a percentage of the balance, so it falls as the balance falls, which stretches the term far longer than a fixed amount would.

The extra payment field is compared against the base payment to show the time and interest it saves.

Rates used · 2026/27

Typical purchase APR20% to 30%
Typical minimum payment1% of balance plus interest, or £5
Interest-free periodsend dates matter, the rate jumps afterwards
Payment assumed herefixed, not a falling percentage

Last checked July 2026. Source: HMRC and gov.uk.

Worked example

A £3,000 balance at 24.9% paying £100 a month takes 4 years to clear and costs £1,744 in interest, so £4,744 repaid on £3,000 borrowed. Adding £50 a month clears it in 2 years 3 months and saves £828.

Common questions

Why does the minimum payment take so long?

Because the issuer minimum is usually a percentage of the balance, so it shrinks as the balance does. Paying a fixed amount instead is one of the single most effective things you can do.

What does APR actually mean here?

It is the annual rate. Monthly interest is roughly one twelfth of it, applied to whatever you still owe, which is why the first payments barely dent the balance.

Should I move the balance to a 0% card?

That is a decision for you and depends on the transfer fee and whether you can clear it before the offer ends. This calculator shows what the current card costs, which is the number worth comparing against.

What if I keep spending on the card?

Then this understates the time and cost. The calculation assumes no further spending on the balance.

This is an estimate, not financial advice. The result is arithmetic based on the figures you entered and the published rates listed above. It does not account for your full circumstances and should not be the only basis for a decision. For advice specific to you, speak to a qualified adviser.