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Debt snowball calculator UK
A debt snowball calculator shows the order to clear your debts, smallest balance first, and when you could be debt-free. Free for UK credit cards, loans and overdrafts, with no sign-up.
Your details
Add your debts and payment assumptions, then compare snowball with avalanche.
Results
Compare your payoff strategies
Run the plan to compare payoff timing, total interest, and the month-by-month path for each strategy.
Your payoff comparison will appear here
Add your debts and run the calculator.
How it works
How the debt snowball works
Clear the smallest balance first
Pay the minimum on everything, then put any extra money towards the smallest balance, whatever its interest rate.
Roll each payment forward
When a debt is cleared, add its payment to the next smallest balance. Your monthly payment grows like a snowball until every debt is gone.
Guide
The debt snowball method, explained for UK debts
What the snowball is, how to use the calculator, a worked example in pounds, and when a different approach makes more sense.
What is the debt snowball method?
The debt snowball is a way to pay off several debts by clearing the smallest balance first, whatever its interest rate. You keep paying the minimum on everything else and put any spare money towards the smallest debt. When it is cleared, its payment moves to the next smallest, so the amount you pay off each month keeps growing.
The appeal is momentum. Closing whole accounts early gives you visible wins, fewer payments to juggle and a reason to keep going. For many people that matters more than squeezing out the last pound of interest.
How to use the debt snowball calculator
You need four things for each debt, all of which are on your latest statement or in your banking app:
- Balance: what you owe today.
- APR: the yearly interest rate. For an overdraft, use its yearly overdraft rate.
- Minimum payment: the least you have to pay each month. For an overdraft, enter what you plan to pay off.
- Extra monthly payment: anything you can pay on top of all your minimums. This is the biggest lever on your debt-free date.
Run the plan to see which debt to clear first, the month each debt is paid off, your total interest and your estimated debt-free date. You can switch to the avalanche order at any time to compare. Prefer to keep it in a spreadsheet? Download the free debt snowball spreadsheet for Excel or Google Sheets.
Worked example: clearing £8,000 with the debt snowball
Here is a typical mix of UK debts. The minimum payments add up to £260 a month, and this household can find an extra £150, so £410 goes towards debt every month.
| Debt | Balance | APR | Minimum | Cleared in |
|---|---|---|---|---|
| Store card | £400 | 29.9% | £25 | Month 3 |
| Overdraft | £900 | 39.9% | £40 | Month 7 |
| Credit card 1 | £2,400 | 24.9% | £75 | Month 16 |
| Credit card 2 | £4,300 | 21.9% | £120 | Month 25 |
- Paying only the £260 of minimums takes 50 months and costs about £4,791 in interest.
- Adding £150 a month with the snowball clears everything in 25 months, with about £2,182 of interest.
- That is 25 months sooner and roughly £2,609 less interest.
The store card is gone by month 3. Its payment then moves to the next debt, and so on down the list. The avalanche order would clear the overdraft first, in month 6, and finish in 25 months for about £2,161: just £21 less than the snowball.
In other words, the extra £150 a month makes a far bigger difference than the order you choose. Try your own numbers in the calculator above.
Debt snowball vs debt avalanche
| Debt snowball | Debt avalanche | |
|---|---|---|
| Pays first | Smallest balance | Highest interest rate |
| Total interest | Usually a little more | Usually the least |
| First debt cleared | Usually sooner | Can take longer |
| Best for | Staying motivated with quick wins | Paying the lowest total cost |
Both methods use the same total payment; they only change the order. Read more about the debt avalanche calculator, or run both on your own debts with the snowball vs avalanche calculator and pick the one you are most likely to stick with.
What the debt snowball doesn't cover
The snowball is for non-priority, unsecured debts: credit cards, store cards, overdrafts, personal loans, car finance and buy now pay later. Keep two other kinds of debt out of it.
- Priority debts, such as rent or mortgage arrears, Council Tax, gas and electricity, court fines, TV Licence, child maintenance and tax owed to HMRC. Missing these can lead to eviction, disconnection or enforcement, so they always come first. MoneyHelper explains how to prioritise your debts.
- Secured debts, such as your mortgage, which run on their own schedule. The mortgage overpayment calculator is a better fit for those.
If you can't afford your minimum payments
The snowball only works if you have money left after your minimums. If you are already missing payments, start with free debt advice instead. It is free, confidential and won't judge you.
- Breathing Space gives you up to 60 days' legal protection from most creditor action in England and Wales while you get advice, with most interest and charges frozen. A debt adviser can apply for you. Read about Breathing Space on GOV.UK.
- A debt management plan can lower your monthly payments to what you can afford. Free providers such as StepChange don't charge for setting one up.
How we calculate
Each month the calculator adds interest to every balance at its APR divided by 12, takes off your payments, and repeats until every balance reaches zero. In snowball order:
- Every debt gets its minimum payment, which stays the same each month until that debt is cleared.
- Your extra payment goes to the smallest balance. If two balances are equal, the one with the higher APR goes first.
- When a debt is cleared, its minimum payment rolls onto the next debt in the order.
It assumes your rates stay the same, you make every payment and you don't borrow more. Promotional rates, fees and changes in your circumstances will move the real date, so treat it as an estimate and rerun it when something changes.
Educational information only. Zero Debt is not regulated by the Financial Conduct Authority (FCA) and this calculator is not financial advice. For advice about your situation, speak to a free debt advice service.
Sources
Debt snowball calculator FAQs
Is this debt snowball calculator free?
Yes. The calculator is free and works in your browser without an account. Enter your debts and you get your payoff order, total interest and estimated debt-free date straight away.
Should I include my student loan in a debt snowball?
Usually not. UK student loans (Plans 1, 2, 4 and 5 and Postgraduate Loans) are repaid through your pay as a percentage of what you earn above a threshold, and any balance left is written off after a set number of years. They behave very differently from credit cards and loans, so most people leave them out and focus the snowball on commercial debt.
See repaying your student loan on GOV.UK for the current thresholds.
How do FCA minimum payment rules affect the snowball?
Under FCA rules (CONC 6.7.5R), a credit or store card minimum payment must at least cover that month's interest, fees and charges plus 1% of the balance. As your balance falls, so does the minimum on your statement.
To keep the snowball rolling, keep paying the same amount rather than dropping to the lower minimum. This calculator assumes you do that: each minimum payment stays fixed until the debt is cleared. Our study of what minimum payments really cost shows how much difference that makes.
What is persistent credit card debt?
You are in persistent debt if, over 18 months, you have paid more in interest, fees and charges than you have paid off the balance. Your card provider must contact you at 18 and 27 months. At 36 months they must offer you a way to repay faster, and they can suspend the card if you cannot.
Clearing smaller cards first with the snowball, while overpaying, is one way to stop a card drifting into persistent debt.
Can I include Klarna, Clearpay or other buy now pay later plans?
Yes. Enter each plan as its own debt, with the amount left to pay as the balance, 0% as the APR (unless you are being charged interest) and your instalment as the minimum payment. Buy now pay later balances are often small, so they tend to sit at the top of a snowball and clear early.
How do I add an overdraft?
Enter your overdrawn amount as the balance and your overdraft rate as the APR. Arranged overdrafts are charged at a single yearly rate, often around 35% to 40%, so check your bank app or statement.
Overdrafts have no required monthly payment, so enter the amount you plan to pay off each month as the minimum payment.
Should I use a 0% balance transfer alongside the snowball?
It can help. Moving a high-rate card balance to a 0% deal means more of each payment clears the balance instead of interest. Check the transfer fee and when the 0% period ends, and aim to clear the balance before the rate goes up.
The balance transfer calculator shows whether a deal saves you money and what you need to pay each month to clear it in time.
Is the debt snowball or the debt avalanche better?
The debt avalanche, which pays the highest interest rate first, usually costs a little less in interest. The snowball, which pays the smallest balance first, clears whole debts sooner, which many people find easier to stick with.
In the worked example on this page the difference is £21 over 25 months. Run your own debts through the snowball vs avalanche calculator to see the difference for you.