If you are juggling more than one debt — a couple of credit cards, an overdraft, maybe a loan — the order you clear them in matters more than most people realise. Two well-known methods, the snowball and the avalanche, tackle the same debts in opposite orders, and each has a genuine case. One saves the most money; the other keeps you motivated enough to finish. Here is how they work and how to choose, with the numbers laid out.
- Avalanche — pay off the highest interest rate first. Saves the most money overall.
- Snowball — pay off the smallest balance first. Builds momentum with quick wins.
- Either way: pay the minimum on everything, then throw all spare cash at one target debt.
- A 0% balance transfer can supercharge both by pausing interest entirely.
The principle both methods share
Whichever you choose, the engine is the same. You make the minimum payment on every debt to stay current, then direct every spare pound at one chosen debt until it is gone. When that debt clears, its old payment rolls onto the next target — the payment amount snowballs upward even as the number of debts falls. The methods only differ in which debt you attack first.
The avalanche: cheapest by the numbers
The avalanche targets the debt with the highest interest rate first, regardless of its size. Mathematically this is optimal — you are always killing the most expensive debt, so you pay the least interest and clear everything fastest in pure money terms.
Imagine three debts:
| Debt | Balance | APR |
|---|---|---|
| Card A | £1,000 | 29.9% |
| Card B | £3,000 | 22.9% |
| Overdraft | £1,500 | 39.9% |
The avalanche says: overdraft first (39.9%), then Card A (29.9%), then Card B (22.9%) — because that order minimises the interest you hand over. Over the life of the debt this saves the most. Our debt payoff planner runs both methods on your actual balances so you can see the difference.
The snowball: built for motivation
The snowball ignores interest rates and targets the smallest balance first. In the example above that means Card A (£1,000), then the overdraft, then Card B. You clear a whole debt quickly, feel the win, and that momentum keeps many people going where a slow grind would have them give up.
It is not mathematically optimal — you may pay a little more interest — but personal finance is behavioural as much as numerical. A method you actually stick to beats a perfect plan you abandon in month three. For many people the snowball's psychological boost is worth the small extra cost.
Which should you choose?
If you are disciplined and motivated by saving money
use the avalanche. It is the cheapest route, full stop.
If you have struggled to stick with debt repayment before
use the snowball. The quick wins keep you in the game.
If your highest-APR debt is also your smallest
lucky you; both methods agree, so just start.
There is no wrong answer. The best method is the one you will follow to the end.
Supercharge either with a 0% balance transfer
Both methods get dramatically faster if you stop the interest. A 0% balance-transfer card moves expensive debt onto a card charging no interest for a set period, for a one-off fee of typically 1–3%. While the interest is paused, every pound you pay goes to clearing the balance rather than feeding the lender.
Clear it before the 0% period ends The risk with a balance transfer is reaching the end of the 0% window with a balance left, when the card reverts to a high APR — often 20% or more. Set a monthly payment that clears the debt inside the deal, keep paying at least the minimum, and avoid spending on the card. The balance transfer calculator checks whether the fee is worth the interest you save.
Don't forget the basics
No repayment method works if more debt keeps arriving. Pause new spending on the cards, build even a small emergency buffer so a surprise bill does not send you back to credit, and if the debt feels unmanageable, free help from StepChange or Citizens Advice is genuinely good and judgement-free. The credit card payoff calculator shows how long a single card takes to clear at different monthly payments — often a wake-up call that spurs action.
Frequently asked questions
The avalanche saves the most money by targeting the highest interest rate first. The snowball clears small debts first for motivation. Choose the avalanche if you are disciplined, the snowball if you need quick wins to stay on track.
Highest-interest first is cheapest (avalanche). Smallest-balance first is more motivating (snowball). Both keep minimum payments on everything else while you focus spare cash on one debt.
Yes, if used well. Pausing interest for a fee of 1–3% lets every payment reduce the balance. The key is clearing the debt before the 0% period ends to avoid the high revert rate.
Minimum-only payments clear debt very slowly and cost a lot in interest. Even a small extra amount each month, focused on one debt, makes a big difference — and free debt advice can help if you are stuck.
Generally yes. Reducing balances lowers your credit utilisation, a major scoring factor, and clearing debts reduces your commitments — both help over time.
This is general information, not debt advice. If you are struggling, free regulated help is available from StepChange, National Debtline and Citizens Advice.