UK credit cards average 23.9% APR; store cards can reach 29.9%. Enter your balances and monthly budget to see exactly how much interest each strategy costs — and when you'll be debt-free.
Take three common UK debts: £3,500 credit card at 23.9% APR (£70 min), £1,200 store card at 29.9% APR (£30 min), and £6,000 personal loan at 12% APR (£130 min). With a £400/month total budget and the avalanche method, you clear the 29.9% store card first — saving roughly £300 in interest versus snowball over the payoff period.
Both strategies start the same: pay the minimum on every debt each month. The difference is where any remaining budget goes.
Avalanche piles the surplus onto the highest-rate debt. In the UK context, that's often a store card (29.9%+) or an unauthorised overdraft. Clearing these first minimises the total interest you pay.
Snowball piles the surplus onto the smallest balance. You eliminate individual debts faster, which feels motivating — but if a small debt has a low rate, you're leaving high-rate debt to compound unchecked.
UK minimum payments are typically 1–3% of the outstanding balance or £25, whichever is higher. This calculator uses the minimum you enter, so check your last statement for the exact figure.
For a deeper dive into the mathematics and the behavioural research, see our guide to the debt avalanche method.
Both methods have you pay minimums on all debts, then direct extra budget at one target. Snowball targets the smallest balance first; avalanche targets the highest APR first, minimising total interest paid.
Avalanche is always mathematically optimal — it minimises the rate at which interest accrues across your whole portfolio.
Research suggests many people stick better with the snowball because eliminating individual debts provides visible progress. If the interest saving is small, choose whichever method you'll actually follow through on.
UK minimum payments are typically 1–3% of the balance or £25. They are designed to keep you paying for years. Even an extra £50/month directed at your highest-rate debt can cut years off your timeline.
UK credit cards average around 23.9% APR. UK store cards can reach 29.9% or higher. Many bank overdrafts have been standardised to around 39.9% following FCA rules. Always check your actual statement for the exact rate.
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