YourFinanceCoach

Credit card interest calculator

Find out how long a card balance takes to clear, and how much of your repayments is interest.

The purchase rate on your card. UK cards quote this as an APR.

How much do you pay each month?

Leave blank if you have stopped using the card.

Interest is charged

Most issuers apply a daily rate. Monthly uses the simpler APR ÷ 12.

Time to clear the balance

2 years 2 months

You would pay £775.92 in interest — 20.55% of everything you hand over.

Total interest
£775.92
Total repaid
£3,775.92
First month’s interest
£55.24

Charged before any of your payment reaches the balance.

Monthly rate
1.841198%

Implied by the APR.

Month-by-month breakdown (26 months)
Interest, payment and balance for each month
MonthOpeningInterestPaymentClosing
1£3,000.00£55.24£150.00£2,905.24
2£2,905.24£53.49£150.00£2,808.73
3£2,808.73£51.71£150.00£2,710.44
4£2,710.44£49.90£150.00£2,610.34
5£2,610.34£48.06£150.00£2,508.40
6£2,508.40£46.18£150.00£2,404.58
7£2,404.58£44.27£150.00£2,298.85
8£2,298.85£42.33£150.00£2,191.18
9£2,191.18£40.34£150.00£2,081.52
10£2,081.52£38.32£150.00£1,969.84
11£1,969.84£36.27£150.00£1,856.11
12£1,856.11£34.17£150.00£1,740.28
13£1,740.28£32.04£150.00£1,622.32
14£1,622.32£29.87£150.00£1,502.19
15£1,502.19£27.66£150.00£1,379.85
16£1,379.85£25.41£150.00£1,255.26
17£1,255.26£23.11£150.00£1,128.37
18£1,128.37£20.78£150.00£999.15
19£999.15£18.40£150.00£867.55
20£867.55£15.97£150.00£733.52
21£733.52£13.51£150.00£597.03
22£597.03£10.99£150.00£458.02
23£458.02£8.43£150.00£316.45
24£316.45£5.83£150.00£172.28
25£172.28£3.17£150.00£25.45
26£25.45£0.47£25.92£0.00

Fees, cash-advance rates and penalty rates are not included, and a promotional rate ending part-way through is not modelled. Paying the statement balance in full by the due date usually means no interest on purchases at all.

How this is worked out

Monthly interest = balance × [(1 + APR ÷ 365)^(365 ÷ 12) − 1]

What this assumes

A calculator is only as good as what it leaves out. These are the assumptions built into the result above.

  • Interest accrues daily by default, which is how most card issuers charge. Switch to monthly for the simpler APR ÷ 12 convention.
  • The APR is fixed. A promotional rate ending mid-way is not modelled.
  • Paying in full each month before the due date usually means no interest at all on purchases — this tool models a balance that is carried.
  • Fees, cash-advance rates and penalty rates are not included.

Educational information only. This page explains how something works in the United Kingdom. It is not financial advice and does not take account of your circumstances. Rates, fees and eligibility change without notice — check the provider’s own terms before you act.

For free, impartial guidance, see MoneyHelper. To complain about a firm, contact the Financial Ombudsman Service.

Guides that go with this tool