Debt Avalanche Calculator — Fastest Debt Payoff

Debt Avalanche Guide

How the Debt Avalanche Works?

Step 1: list all debts with their interest rates, balances, and minimum payments. Step 2: pay the minimum on every debt every month — never miss a minimum. Step 3: throw any extra money at the debt with the HIGHEST interest rate. Step 4: when that debt is paid off, add its payment to the next highest-rate debt (the 'avalanche' cascade). The avalanche method is mathematically optimal — it minimises total interest paid. The debt snowball (pay smallest balance first) is psychologically easier but can take longer to clear the highest-rate debt if it also happens to be the largest balance.

What's the difference between Avalanche and Snowball?

Avalanche: highest interest rate first. Minimises total interest paid — the mathematically optimal approach. Best for: large differences in interest rates (e.g. 28% credit card vs 6% loan), people motivated by saving money. Snowball: smallest balance first. Provides quicker 'wins' (debts eliminated sooner). Best for: people who need psychological motivation to stay on the plan, where interest rates are similar. Research: studies suggest the snowball method has better real-world completion rates for exactly this reason — the psychological wins matter more than the maths for many people, even though avalanche saves more in total interest.

What should I know about Freeing Up Cash for Extra Payments?

Even small extra monthly payments accelerate payoff dramatically. Sources of extra funds: spending audit — subscriptions, takeaways, and impulse purchases. Sell unused items. Side income. Annual bonus — apply entirely to highest-rate debt. Tax refund. Gift Aid higher-rate relief claim. Balance transfer: moving high-rate credit card debt to a 0% balance transfer card (typically 24-36 months 0% fee of 2-3%) can effectively pause interest entirely. On 0% debt: all payment goes to principal. Minimum payments on all other debts should continue as normal — the extra cash freed up goes toward the highest-interest remaining debt, not spread across everything.

What do I need to know about After Becoming Debt-Free?

When the last debt is paid off, redirect the full payment amount to savings and investment. The same monthly amount that cleared debt will grow substantially when invested. A typical debt repayment of £500/month invested for 20 years at 7% annual return = approximately £260,000. Emergency fund first: 3-6 months expenses in an accessible savings account — prevents new debt from unexpected costs. Then: ISA allowance (£20,000/year), pension contributions (employer matching first — free money), then