Debt Payoff Strategy Calculator
Compare avalanche and snowball repayments, see the cost of each strategy and explore what extra payments change.
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Your numbers
Illustrative figures to start. Change them to explore your decision.
For non-priority debts. Deal with priority bills and arrears first. If the minimums are unaffordable, use the free debt-advice link below.
Your perspective
Avalanche 22 months. Snowball 22 months.
Choose an order you can sustain
Monthly strategy budget: £250.00. Cleared payments stay in the budget.
Avalanche costs £199.60 less interest in this model. Highest-rate-first usually minimises interest; smallest-balance-first may make early progress feel more tangible.
Minimum-only: 55 months and £2,115.06 interest, without rolling cleared payments over.
Extra payments and rolling the budget over save 33 months and £1,337.64 interest compared with minimum-only.
Avalanche payoff order and monthly schedule
Actual clearance order: Credit card → Personal loan.
| Month | Payment | Interest | Left | Cleared |
|---|---|---|---|---|
| 1 | £250.00 | £70.00 | £4,320.00 | — |
| 2 | £250.00 | £67.07 | £4,137.07 | — |
| 3 | £250.00 | £64.08 | £3,951.15 | — |
| 4 | £250.00 | £61.03 | £3,762.18 | — |
| 5 | £250.00 | £57.93 | £3,570.11 | — |
| 6 | £250.00 | £54.78 | £3,374.89 | — |
| 7 | £250.00 | £51.57 | £3,176.46 | — |
| 8 | £250.00 | £48.29 | £2,974.75 | — |
| 9 | £250.00 | £44.95 | £2,769.70 | — |
| 10 | £250.00 | £41.56 | £2,561.26 | — |
| 11 | £250.00 | £38.09 | £2,349.35 | — |
| 12 | £250.00 | £34.57 | £2,133.92 | — |
| 13 | £250.00 | £30.98 | £1,914.90 | — |
| 14 | £250.00 | £27.32 | £1,692.22 | — |
| 15 | £250.00 | £23.60 | £1,465.82 | — |
| 16 | £250.00 | £19.80 | £1,235.62 | — |
| 17 | £250.00 | £15.93 | £1,001.55 | — |
| 18 | £250.00 | £11.99 | £763.54 | — |
| 19 | £250.00 | £7.98 | £521.52 | — |
| 20 | £250.00 | £3.88 | £275.40 | Credit card |
| 21 | £250.00 | £1.84 | £27.24 | — |
| 22 | £27.42 | £0.18 | £0.00 | Personal loan |
Snowball payoff order and monthly schedule
Actual clearance order: Personal loan → Credit card.
| Month | Payment | Interest | Left | Cleared |
|---|---|---|---|---|
| 1 | £250.00 | £70.00 | £4,320.00 | — |
| 2 | £250.00 | £68.40 | £4,138.40 | — |
| 3 | £250.00 | £66.78 | £3,955.18 | — |
| 4 | £250.00 | £65.14 | £3,770.32 | — |
| 5 | £250.00 | £63.49 | £3,583.81 | — |
| 6 | £250.00 | £61.81 | £3,395.62 | — |
| 7 | £250.00 | £60.12 | £3,205.74 | — |
| 8 | £250.00 | £58.40 | £3,014.14 | — |
| 9 | £250.00 | £56.66 | £2,820.80 | — |
| 10 | £250.00 | £54.91 | £2,625.71 | Personal loan |
| 11 | £250.00 | £52.51 | £2,428.22 | — |
| 12 | £250.00 | £48.56 | £2,226.78 | — |
| 13 | £250.00 | £44.54 | £2,021.32 | — |
| 14 | £250.00 | £40.43 | £1,811.75 | — |
| 15 | £250.00 | £36.24 | £1,597.99 | — |
| 16 | £250.00 | £31.96 | £1,379.95 | — |
| 17 | £250.00 | £27.60 | £1,157.55 | — |
| 18 | £250.00 | £23.15 | £930.70 | — |
| 19 | £250.00 | £18.61 | £699.31 | — |
| 20 | £250.00 | £13.99 | £463.30 | — |
| 21 | £250.00 | £9.27 | £222.57 | — |
| 22 | £227.02 | £4.45 | £0.00 | Credit card |
A worked example
A £1,200 debt at 0%, with a fixed £100 monthly minimum, takes 12 payments. An extra £100 per month reduces that to six. At 12% nominal annual interest, a £1,000 balance charged monthly with £600 payments clears with £600 then £414.10: £14.10 interest in total.
What this calculation assumes
- For non-priority consumer debts only. Rent, mortgage arrears, council tax and other priority bills need attention based on the consequences of non-payment, not their APR. Get free debt advice if minimums are unaffordable.
- Rates and entered minimum payments stay fixed. Interest is estimated monthly at APR ÷ 12, rounded to pennies; actual lenders may use daily interest, effective rates, changing minimums or promotional expiry dates. No new borrowing, fees or early-settlement charges.
- Both strategies retain the same total budget, rolling cleared minimums into the next debt. Avalanche targets the highest APR; snowball the smallest balance after that month’s minimums. Ties use balance/APR, then the original identifier.
- The minimum-only comparison does not roll payments over. A partial final payment is capped at the amount owed, with spare budget passed to the next debt in the same month. This is a month-end schedule, not an exact daily settlement forecast. Projections stop at 100 years or when the total payment cannot reduce the balance.
Sources and rules
Rules and guidance checked 5 October 2026. Rates entered in mortgage, debt and car comparisons are your assumptions, not live offers.
Put the numbers in perspective
Illustrative information, not personal financial, tax or debt advice. Check your circumstances and contractual terms before acting. Read our disclaimer.