Debt Payoff Planner

Debt Payoff Guide

Avalanche vs snowball: which debt strategy is right for you?

When you have multiple debts, the order in which you pay them down makes a significant difference, both to the total interest you pay and to how motivated you stay throughout the process. There are two main strategies, each with real advantages.

The avalanche method (highest interest first)

The avalanche method targets the debt with the highest interest rate first, regardless of balance size, while paying minimums on everything else. Once the most expensive debt is cleared, you roll its payment into the next highest-rate debt. Mathematically this is the optimal strategy: you minimise the total interest paid and pay off all debts in the shortest time possible. The downside is psychological, if your highest-rate debt also has a large balance, progress can feel slow and it may be months before you eliminate your first debt.

The snowball method (smallest balance first)

The snowball method targets the debt with the smallest balance first, regardless of interest rate, paying it off as quickly as possible before moving to the next. Each debt you eliminate frees up its minimum payment to add to the next, creating a growing "snowball" of payments. The mathematical cost is paying more interest overall, but the psychological benefit of crossing debts off the list quickly is real. Research by the Harvard Business Review suggests the snowball produces better completion rates for people who struggle to stay motivated.

Which should you choose?

If the avalanche saves you a meaningful amount, say, £500 or more, and your highest-rate debt isn't enormous, avalanche is likely the better choice. If the difference is small (as it often is when balances are similar), or if you know you'll need early wins to stay on track, snowball may serve you better. The best strategy is the one you actually stick to. Use the calculator above to see exactly how much the difference is in your situation.

The power of extra payments

Even small extra payments can dramatically reduce your payoff timeline and total interest. Adding £50 a month to a £5,000 credit card at 24.9% APR, on top of the minimum payment — can cut the repayment period from years to months and save hundreds in interest. The earlier in the repayment process you add extra payments, the greater the impact, because interest compounds on the outstanding balance.

Balance transfers and consolidation

Before choosing a payoff method, it's worth checking whether a 0% balance transfer card or a debt consolidation loan could reduce the interest rate on your expensive debts. Moving high-rate credit card debt to a 0% card (where you pay a one-off transfer fee, typically 2–3%) and then paying it down aggressively can be cheaper than any payoff strategy. However, consolidation only helps if you stop adding new debt, otherwise the cycle continues.