Free UK Tool

Debt Payoff Calculator

Add your debts, choose avalanche or snowball strategy, and see exactly when you'll be debt-free — and how much interest you save.

This extra amount is applied each month to your target debt on top of all minimum payments. When a debt is cleared, its minimum gets rolled in automatically.

Your Debts
Debt Name Balance (£) Interest Rate (%) Min Payment (£/mo)
Debt-Free In
With your chosen strategy
Total Interest
Total interest paid
Total Debt
Current balance across all debts
Total Repaid
Balance + all interest
Warning: At least one debt will take very long to pay off at the current minimum payment — the minimum may barely cover the interest. Consider increasing the minimum payment or adding extra payments.
Minimum Payments Only
Debt-free in—
Total interest—
Total repaid—
With Extra Payments (Avalanche)
Debt-free in—
Total interest—
Total repaid—
Interest Saved
—
vs paying minimums only
Time Saved
—
vs paying minimums only
Payoff Order
# Debt Starting Balance Interest Paid Debt-Free

Avalanche vs Snowball: Which Should You Use?

Both the avalanche and snowball methods involve paying the minimum on all your debts and putting any extra money towards one target debt at a time. The difference is how you choose that target.

Debt Avalanche

Attack the highest interest rate debt first. Once it's cleared, roll that payment into the next highest rate. This is the mathematically optimal approach — it minimises the total interest you pay, often by hundreds or thousands of pounds compared to paying minimums only.

Debt Snowball

Attack the smallest balance first, regardless of interest rate. You clear debts faster and get more frequent "wins". Research by Harvard Business School found that people using the snowball method were more likely to stay motivated and become debt-free, even though they pay slightly more interest than the avalanche method.

The Freed Payment Effect

The real power of both methods comes from rolling freed minimums. When you clear a debt, you don't reduce your total monthly payment — you redirect that freed-up minimum into your next target. Each cleared debt accelerates the next one, snowballing (or avalanching) until you're completely debt-free. Once you are, redirect that same total monthly payment into savings — use the Savings Goal Calculator to see how quickly your emergency fund or house deposit can grow. If you want to track the impact on your overall financial picture, the Net Worth Tracker shows your debt-to-asset ratio in real time.

Frequently Asked Questions

The debt avalanche method means paying the minimum on all debts, then putting any extra money towards the debt with the highest interest rate. Once the highest-rate debt is cleared, you roll that payment into the next highest-rate debt. This method minimises the total interest you pay and is mathematically optimal.
The debt snowball method means paying the minimum on all debts, then putting extra money towards the debt with the smallest balance. Once that debt is cleared, you roll its payment into the next smallest. This method pays off individual debts faster, which provides psychological wins that help many people stay motivated.
The avalanche method saves more money in interest — sometimes thousands of pounds. The snowball method often leads to better outcomes in practice because clearing debts early provides motivation to continue. If your interest rates are similar across debts, the difference is small and the snowball's motivational advantage may outweigh it.
A good rule of thumb: if your debt interest rate is higher than what you can earn on savings, pay off the debt first. Credit card debt at 20%+ should almost always be prioritised over saving at 4–5%. However, it's usually worth maintaining a small emergency fund (£1,000–£3,000) even while paying off debt, so unexpected expenses don't send you back into debt.
Even £50–£100 extra per month can dramatically shorten your debt repayment timeline and save significant interest. Use this calculator to see the exact impact of different extra payment amounts. In general, any extra is better than none — the key is consistency. Once you're debt-free, redirect that same total monthly payment into savings or investments.
In the avalanche and snowball methods, when one debt is cleared you don't reduce your total monthly payment — you roll that freed-up minimum into your next target debt. This is the core mechanic: each cleared debt accelerates repayment of the remaining ones. This calculator handles this automatically.
Minimum payments vary by lender. Credit cards typically require 1–3% of the outstanding balance or a fixed minimum (e.g. £25), whichever is higher. Personal loans and car finance (PCP/HP) have fixed monthly instalments. Check your latest statement for your current minimum payment amount.