Compare the debt snowball and avalanche repayment strategies side by side. Enter up to 5 debts to see which method saves more interest and clears your debts sooner.
Last updated: April 2026
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Debt name
Balance
APR %
Min pmt
Any amount above your total minimum payments to accelerate repayment.
Snowball vs Avalanche
Total debt
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Snowball (smallest balance first)
Debt-free in -
Total interest paid -
Avalanche (highest rate first)
Debt-free in -
Total interest paid -
Interest saved (avalanche vs snowball) -
Snowball versus avalanche: which is better?
Both the debt snowball and debt avalanche are systematic repayment strategies that use the same total monthly payment. The difference is only in which debt receives the extra payment each month.
The snowball method targets the smallest balance first, regardless of interest rate. When a debt is cleared, its minimum payment is rolled into the next smallest. This creates psychological wins early, which research suggests helps people stay motivated and stick to the plan.
The avalanche method targets the highest interest rate first. This is mathematically optimal - it minimises total interest paid and typically clears debt slightly faster. The gap between the two methods in total interest paid depends on the rate differential between debts.
Which should you choose?
If the interest difference between your highest and lowest rate debts is small, the total cost difference between strategies is modest - choose whichever keeps you motivated. If you have a high-rate debt (overdraft at 39.9%, store card at 39.9%) alongside lower-rate debts, the avalanche method saves meaningfully more. If you have one very small balance that is emotionally draining to carry, clearing it first via snowball can be worth the small additional cost for the psychological benefit.
Frequently asked questions
If you stick rigidly to either strategy with the same total monthly payment, the difference in total interest paid is often modest - typically a few hundred pounds on a typical multi-debt portfolio. The bigger variable is whether you actually stick to it. Research on behavioural economics consistently shows that the quick wins from the snowball method improve adherence for many people. If you know yourself to be motivated by momentum, snowball is likely to produce a better outcome in practice even if it costs slightly more in theory.
Typically no. Mortgage debt is secured against your property and carries a much lower interest rate than consumer debt. The snowball and avalanche strategies are most useful for unsecured consumer debt - credit cards, personal loans, overdrafts, store cards. Mortgage overpayment is a separate decision, usually considered after all high-rate consumer debt is cleared. Student loan debt in the UK is also usually excluded, because repayments are income-contingent and the loan writes off after a set period - it behaves differently from conventional debt.
The minimum payment trap is the situation where only paying minimum payments on each debt keeps the balances barely falling because most of each payment is consumed by interest. This calculator adds an extra monthly payment on top of minimums to show the acceleration effect. Even a modest additional payment of £50–£100 per month on a multi-debt portfolio can reduce the time to debt freedom by years and save thousands in interest. The extra payment only needs to be applied to one debt at a time - focusing it rather than spreading it across all debts is what makes the strategies effective.