Illustration of stacked bills, credit cards, and a downward payoff chart.

Debt Payoff

Snowball and avalanche

Enter each debt’s balance, APR, and minimum monthly payment. Choose snowball (smallest balance first) or avalanche (highest APR first). Add an optional extra monthly payment on top of all minimums.

Months to debt-free
Total interest paid
Payoff order

Each month: interest accrues on remaining balances, minimum payments are applied to every debt, then any extra payment goes to the priority debt (and rolls to the next in line if one is cleared in the same month).

How debt snowball and avalanche payoff work

Multiple debts, one plan

Enter each debt’s balance, APR, and minimum monthly payment. Choose snowball (smallest balance first) or avalanche (highest APR first). An optional extra monthly amount is applied on top of all minimums to the current target debt, then rolls to the next when one clears.

Snowball prioritises motivation from early wins. Avalanche usually minimises interest if you stick with it. Neither replaces advice from a regulated counsellor if debts are unmanageable.

Worked example

Three cards with balances £500 / £2,000 / £3,000 and different APRs will show different payoff orders under each strategy. Adding £100 extra monthly shortens both plans; avalanche typically saves more interest when high-APR balances are large.

What is modelled

  • Interest accrues from the APRs you enter (simplified monthly treatment).
  • Minimums continue on debts not currently targeted.
  • Fees, penalty rates, and deferred interest promotions are not automatic.

Common mistakes

  • Stopping extra payments after the first win.
  • Ignoring a 0% promo end date that spikes APR.
  • Listing minimums that do not actually cover interest (balance grows).

FAQs

Should I include the mortgage?
You can, but mortgage strategy often differs — see Mortgage for payment maths on a single home loan.
Is this a hard offer quote?
No — illustrative scheduling only.

When this page helps

Use it when you want a transparent, browser-side calculation with the assumptions spelled out — then verify anything high-stakes against primary docs, a professional, or your own measurements. The related links below point to sibling tools and longer guides when you need more context.

Accuracy notes

Results depend entirely on the numbers you enter and the simplified model described above. Device clocks, tape measurements, market rates, and recipe conventions can all differ from a perfect textbook case. If an output looks surprising, re-check units first, then re-read the formula section.

Related: Loan, Interest, Mortgage.

Last updated: July 2026