How to Pay Off £10,000 of Debt — Avalanche vs Snowball Worked Example
Here’s a real worked example with £10,000 of debt across three typical UK accounts. We’ll run both the avalanche and snowball methods with the same extra payment so you can see exactly how interest and payoff order differ.
The scenario
Imagine you have:
| Debt | Balance | APR | Min payment |
|---|---|---|---|
| Store card | £900 | 34.9% | £25 |
| Credit card | £3,500 | 22.9% | £70 |
| Personal loan | £5,600 | 9.9% | £126 |
Total minimums = £221/month. You decide to pay an extra £100 per month (£321 total toward debt). We’ll compare avalanche vs snowball with that same £100 extra.
Payoff order
Avalanche (highest interest first): Store card (34.9%) → Credit card (22.9%) → Personal loan (9.9%).
Snowball (smallest balance first): Store card (£900) → Credit card (£3,500) → Personal loan (£5,600).
In this example the order is the same for both methods because the smallest balance (store card) also has the highest rate. So we’d expect similar results — but avalanche still wins slightly because every extra pound goes to the highest rate until that debt is gone. When the smallest balance isn’t the highest rate, the gap between the two methods gets much bigger. For instance, if your smallest debt had a low APR and your biggest had a high one, snowball would leave that expensive debt growing for longer — and the interest gap could be hundreds or thousands of pounds. You can see that by changing the numbers in our calculator.
Rough results (illustrative)
With the numbers above and £100 extra/month, avalanche typically clears the debt in about 38 months with roughly £2,100 in total interest. Snowball might take a month or two longer and add a few hundred pounds in interest — the exact figures depend on how the minimums and interest round. The point is: same debts, same extra payment, but the order you attack them in changes the total cost and timeline.
To get your exact numbers, plug your own balances, APRs, and minimums into the free avalanche vs snowball calculator. You’ll see total interest and payoff dates for both methods, plus a chart of balance over time. For a deeper explanation of why avalanche usually wins, read Debt Avalanche vs Snowball: Which Saves More Money in the UK?.
Summary for this £10k scenario: With £100 extra/month, avalanche clears the debt in roughly 38 months with about £2,100 in interest; snowball takes a bit longer and costs a bit more. The exact numbers depend on rounding, but the takeaway is clear: the order you pay debts in affects both your timeline and your total cost.
What if you only paid the minimums?
If you paid only the £221 minimum and never added extra, you’d stay in debt for years longer and pay thousands more in interest. That’s the trap of minimum payments in the UK — we break it down in The Real Cost of Only Paying Minimum Payments on UK Credit Cards. Adding even £50–100 a month and targeting high interest first (avalanche) can cut both your timeline and total interest dramatically.
Month-by-month: the first six months (avalanche)
Here’s how the avalanche plays out for the first six months. The extra £100 goes to the store card (34.9% APR) until it’s gone, then rolls down to the credit card.
| Month | Store card | Credit card | Personal loan | Interest this month |
|---|---|---|---|---|
| Start | £900.00 | £3,500.00 | £5,600.00 | — |
| 1 | £773.57 | £3,496.75 | £5,520.63 | £90.95 |
| 2 | £645.65 | £3,493.49 | £5,440.60 | £89.60 |
| 3 | £516.20 | £3,490.22 | £5,359.90 | £88.18 |
| 4 | £385.19 | £3,486.93 | £5,278.51 | £86.72 |
| 5 | £252.58 | £3,483.63 | £5,196.44 | £85.22 |
| 6 | £118.34 | £3,480.31 | £5,113.67 | £83.66 |
| 7 | £0 — cleared | £3,357.52 | £5,030.18 | £81.99 |
The store card is gone by month 7. The £125 that was going to it (£25 minimum + £100 extra) immediately rolls onto the credit card. From month 8 onward, the credit card gets £195/month (£70 + £125), clearing it in roughly another 21 months — then the full £321 attacks the personal loan for the final stretch.
How snowball differs in this example
With snowball you also target the store card first — it’s the smallest balance at £900. So months 1–7 look identical to the avalanche. The difference emerges after the store card is gone. At that point snowball asks: which remaining debt has the smallest balance? That’s the credit card at ~£3,481. The avalanche also picks the credit card (it has the highest APR of the two remaining debts). So in this particular example the methods produce nearly identical results throughout, because the debt order just happens to align. This is the scenario where snowball and avalanche converge.
The gap between methods widens dramatically when your smallest balance has a low rate. For instance, if the scenario were reversed — small balance at 9.9%, large balance at 34.9% — snowball would leave the expensive 34.9% debt growing for months while it cleared the cheap small one first. That’s where the interest difference can be hundreds or thousands of pounds. The calculator lets you change any of the values to see how the gap shifts for your own debts.
What happens if you only pay the minimums?
In this scenario, total minimums are £221/month. If you paid only that and nothing more, the store card alone at 34.9% would take roughly 5–6 years and cost about £850 in interest before it was cleared — and the credit card on minimum payments at 22.9% could drag on for over a decade. Paying even £50 extra per month and directing it at the store card cuts years off the timeline and saves hundreds in interest. Adding £100 (bringing you to £321 total as in this worked example) saves even more and gets you debt-free in roughly 3 years. For a deeper look at the minimum payment trap, see The Real Cost of Only Paying Minimum Payments on UK Credit Cards.
What to do with your own numbers
This scenario uses three debts that are fairly typical for someone carrying a mix of UK credit, but your own situation will be different. The key variables are: the spread of APRs across your debts, whether your highest-rate debt also happens to be your smallest balance, and how much extra you can realistically pay each month. To see your own worked example:
- Pull out each statement — you need the current balance, APR, and minimum payment for each debt.
- Add up your minimum payments and decide how much on top of that you can commit each month.
- Enter everything into the free calculator — it shows avalanche vs snowball side by side with your exact interest and payoff date.
Takeaway
Same £10k, same extra £100/month — the method (avalanche vs snowball) changes how much you pay in interest and how fast you’re done. In this example the difference is small because the debt order aligns; with a different APR distribution, the gap can be much larger. Use the calculator with your real debts to see your own worked example in under two minutes.
Frequently asked questions
How much interest will I pay on £10,000 of debt using the avalanche method?
In this scenario — store card 34.9%, credit card 22.9%, personal loan 9.9%, with £100/month extra — the avalanche pays off the full £10,000 in roughly 38 months with about £2,100 in total interest. Snowball gives nearly identical results here because the smallest balance also happens to be the most expensive. When those don't align, avalanche can save hundreds or thousands more.
Why do avalanche and snowball give the same results in this example?
Because the smallest balance (store card, £900) also carries the highest APR (34.9%). Both methods agree on the attack order, so the results converge. The gap widens dramatically when your smallest debt has a low APR — snowball then leaves your most expensive debt compounding unchecked. That's when avalanche can save hundreds or thousands of pounds over snowball.
What happens to the payment when I clear a debt?
The full amount you were paying — minimum plus extra — immediately rolls to the next priority. In this example, when the store card clears at month 7, the £125 that was going to it (£25 min + £100 extra) cascades to the credit card. That debt now receives £195/month instead of £70, clearing it roughly 21 months later. This payment roll is what makes the avalanche accelerate: each cleared debt adds firepower to the next.
How long does it take to pay off £10,000 of debt in the UK?
With £100/month extra on top of minimums (£321 total), about 38 months in this scenario. Paying only the minimum £221 each month with no extra could stretch it to a decade or more and add thousands of pounds in interest. The key drivers are the APRs on your debts and how much extra you can pay. Enter your real numbers in the free calculator to see your exact timeline.
Should I pay off a store card or credit card first?
Compare APRs. UK store cards often sit at 29–39.9%, while credit cards are typically 20–30% — so store cards are usually the higher-rate debt and get the extra payment first under avalanche. If your credit card has a higher APR than your store card, attack that first. The calculator shows the avalanche order automatically once you enter the rates.