See how quickly you can become debt-free by paying off up to three debts using the avalanche method (highest interest rate first).
This debt payoff calculator shows how long it would take to become debt-free across up to three debts, and how much interest you'd pay, using the "avalanche" method — directing any extra payment toward the debt with the highest interest rate first, while making at least the minimum payment on all debts. This is generally the lowest-cost way to pay off multiple debts.
Each month, this calculator applies the minimum payment to every debt, calculating interest and reducing each balance accordingly. Any extra payment (plus the minimum payments freed up from debts already paid off) is then directed entirely toward the debt with the highest interest rate. Once that debt is cleared, the extra payment "rolls over" to the debt with the next-highest rate, and so on, until all debts are paid off.
Formula (per month, per debt): Interest = Balance × (Rate ÷ 12 ÷ 100). Principal Paid = Minimum Payment − Interest. Balance = Balance − Principal Paid. Any extra payment is then applied in full to the highest-rate debt with a remaining balance, reducing its balance directly.
Example: With a £5,000 balance at 22% (£150 minimum) and an £8,000 balance at 12% (£200 minimum), plus a £100 extra monthly payment directed to the higher-rate debt first, both debts would be cleared in roughly 26 months, with total interest of about £2,600 — for a total amount paid of around £15,600 on a combined starting balance of £13,000. (Note: all figures in this example are for illustration purposes only.)
The avalanche method — prioritising extra payments toward the highest interest rate debt — minimises the total interest paid across multiple debts, which is mathematically the most cost-effective approach. An alternative, the "snowball" method, prioritises the smallest balance first regardless of interest rate, which can provide psychological motivation from clearing individual debts faster, even if it costs slightly more in total interest. Whichever method you choose, the key principle is the same: keep paying at least the minimum on every debt (missing minimum payments can damage your credit score and incur fees), and direct any extra money consistently toward one debt at a time rather than spreading it thinly. If your debts include high-APR credit cards, also consider whether a 0% balance transfer card or a debt consolidation loan at a lower rate could reduce the interest you pay while following the same payoff strategy.
The avalanche method directs any extra payment toward the debt with the highest interest rate, while paying at least the minimum on all other debts. Once the highest-rate debt is cleared, extra payments move to the next-highest rate debt, and so on. This approach minimises the total interest paid across all debts.
The avalanche method targets the highest interest rate debt first, minimising total interest paid. The snowball method targets the smallest balance first, regardless of interest rate, which can provide quicker "wins" by clearing individual debts faster — potentially helping with motivation, though it may cost slightly more in total interest.
This calculator assumes you can at least cover the minimum payments on each debt. If you're struggling to meet minimum payments, it's important to seek help early — free, confidential debt advice is available from services such as StepChange, National Debtline, and Citizens Advice, who can help you explore options including payment plans or debt management arrangements.
No. This calculator assumes no further borrowing on the included debts — it shows how long it would take to clear the existing balances. If you continue to add new charges to a credit card included in this calculation, your actual payoff time and total interest will be higher.
It depends. A debt consolidation loan can simplify multiple debts into a single payment and potentially reduce your overall interest rate — but only if the new loan's rate and terms are genuinely better than your existing debts, and if it doesn't encourage taking on additional debt. Compare the total cost carefully, including any fees.
This calculator assumes that once a debt is fully paid off, its minimum payment amount is "freed up" and added to the extra payment pool, increasing the amount directed toward your remaining debts — this is sometimes called the "debt snowball" effect, and it accelerates payoff of subsequent debts.
Disclaimer: The information and figures provided on this page are for educational and illustrative purposes only and do not constitute financial or debt advice. This calculator assumes consistent payments with no missed months and no further borrowing on the included debts. Actual interest charges, fees, and terms vary by lender and account type. If you are struggling with debt, free and confidential advice is available from services such as StepChange, National Debtline, and Citizens Advice. Always consult a qualified financial adviser for guidance specific to your situation.