How to Use This Calculator
Enter your current credit card balance, annual interest rate (APR), and the amount you plan to pay each month. The calculator will show you how long it will take to clear your balance and how much interest you’ll pay in total.
- Your balance is the total amount you currently owe on your credit card
- APR (Annual Percentage Rate) appears on your credit card statement
- Monthly payment should be at least your minimum payment amount
- Try different payment amounts to see how you can reduce interest costs
How Credit Card Interest Works in the UK
Credit card providers calculate interest using the Daily Periodic Rate (DPR), which is your APR divided by 365 days. This interest is applied to your outstanding balance each day.
Calculation Method
Interest is calculated daily and compounded monthly. The formula works as follows:
- Daily Periodic Rate = APR ÷ 365
- Daily Interest = Balance × Daily Periodic Rate
- Monthly Interest = Sum of all daily interest charges
Example Calculation
If you have a £1,000 balance with a 20% APR:
- Daily Periodic Rate = 20% ÷ 365 = 0.0548% per day
- Daily Interest = £1,000 × 0.000548 = £0.55 per day
- Monthly Interest (30 days) = approximately £16.44
Minimum Payments Explained
Most UK credit card providers calculate minimum payments as either a percentage of your balance (typically 1-3%) plus interest, or a fixed minimum amount (usually £5-£10), whichever is higher.
Why Minimum Payments Cost More
Paying only the minimum amount each month means:
- Most of your payment goes towards interest, not reducing your balance
- It takes significantly longer to clear your debt
- You pay substantially more in total interest charges
- You risk falling into persistent debt
Repayment Strategies
1. Pay More Than the Minimum
Even adding £10-£20 to your minimum payment can reduce your repayment time by years and save hundreds in interest.
2. Avalanche Method
If you have multiple cards, focus extra payments on the card with the highest APR whilst maintaining minimum payments on others. This minimises total interest paid.
3. Snowball Method
Pay off the smallest balance first whilst maintaining minimums on larger debts. This provides psychological wins and momentum.
4. Balance Transfer
Consider transferring your balance to a 0% interest card. This allows your entire payment to reduce the principal, though transfer fees typically apply.
5. Fixed Payment Plan
Set up a standing order for a fixed amount above your minimum. This creates consistency and prevents you from reducing payments as your balance decreases.
Common Repayment Scenarios
| Balance | APR | Monthly Payment | Time to Clear | Total Interest |
|---|---|---|---|---|
| £2,000 | 21.5% | £50 (min) | 6 years 3 months | £1,762 |
| £2,000 | 21.5% | £100 | 2 years 1 month | £521 |
| £2,000 | 21.5% | £150 | 1 year 3 months | £298 |
| £5,000 | 21.5% | £100 (min) | 10 years 8 months | £7,854 |
| £5,000 | 21.5% | £200 | 3 years | £2,183 |
| £5,000 | 21.5% | £300 | 1 year 10 months | £1,148 |
These examples demonstrate how increasing your monthly payment dramatically reduces both repayment time and total interest paid.
Frequently Asked Questions
Making Extra Payments Work for You
Small additional payments can create substantial savings over time. Consider these practical approaches:
Round Up Your Payments
If your minimum payment is £47, round it up to £50 or even £75. These small increases accumulate significant savings over the life of your debt.
Use Windfalls Wisely
Apply tax refunds, bonuses, or monetary gifts directly to your credit card balance. This immediately reduces your principal and future interest charges.
Cut One Expense
Identify one monthly subscription or habit you can eliminate temporarily. Redirect that amount to your credit card payment. A £15 monthly saving applied to your balance can reduce your repayment time by months or years.
Weekly Payments
Instead of one monthly payment, make weekly payments of one-quarter of your monthly amount. This reduces your average daily balance and the interest charged, as you’re paying down the principal more frequently.