Enter your debts and monthly budget. See exactly when you'll be debt-free and how much interest each strategy costs — then pick the one that fits your numbers and your personality.
Take three debts: $5,000 credit card at 22% APR ($100 min), $3,000 store card at 26% APR ($75 min), and a $8,000 personal loan at 14% APR ($160 min). With a $500/month total budget and the avalanche method, you tackle the 26% card first — paying roughly $480 less in interest than if you'd used snowball. Both strategies clear all debt within about 30 months.
Both strategies start the same way: pay the minimum on every debt each month. The difference is where any remaining budget goes.
Avalanche piles the surplus onto the debt with the highest interest rate. This shrinks the rate at which interest accrues across your whole portfolio, minimising the total cost.
Snowball piles the surplus onto the smallest balance. You eliminate individual debts faster, which can feel motivating — but you may pay more interest along the way if a small debt has a low APR and a large high-rate debt is sitting untouched.
The calculator runs a month-by-month simulation: interest accrues first (balance × APR / 12), then minimums are paid on all debts, then the remainder of your budget attacks the priority debt. The chart shows your total remaining balance over time under each approach.
For a deeper dive into the mathematics and the behavioural research, see our guide to the debt avalanche method.
Both methods have you pay minimums on all debts, then direct any extra budget at one target debt. The snowball targets the smallest balance first — quick wins build momentum. The avalanche targets the highest-APR debt first — mathematically optimal, as it minimises total interest paid.
Avalanche is always mathematically optimal: by attacking the highest-rate debt first, you reduce the rate at which interest accrues across your total portfolio. The snowball can cost hundreds or even thousands more in interest depending on your debt mix.
Research suggests many people stick better with the snowball because eliminating individual debts provides visible progress and emotional momentum. If the interest difference is small — which happens when balances are similar — the best method is whichever one you will actually follow through on.
Minimum payments are typically set by lenders to keep you indebted as long as possible. They often cover just enough to prevent default. Increasing your extra budget — even by a small amount — dramatically shortens the timeline. This calculator shows you exactly how much.
Globally, credit card APRs typically range from 15% to 30%. The US average is around 22%. UK credit cards average around 23.9%; UK store cards can reach 29.9%. French revolving credit sits around 18%. German credit cards are typically lower at around 16%. Enter your actual card APR from your statement for the most accurate projection.
ProFinanceCast turns one-off calculations into a living 10-year forecast that updates as your income, expenses, and debts change. Free forever for the core forecast.