Debt Snowball Calculator
Pay off your smallest debt first to build momentum. Enter your debts and monthly budget to see your payoff order, estimated debt-free date and how it compares with debt avalanche.
Based on payments starting in January 2026 and a total monthly debt-payment budget of £650.00.
Do this next
Pay the required minimum on every debt, then put your initial extra payment of £350.00 toward Store card first. It has the smallest balance, at £1,200.
Your payoff order
The snowball method targets the smallest remaining balance first. You still make the required minimum payment on every open debt. The APR is shown for transparency, not as the ordering factor.
- Target 1Store card
- Target 2Credit card
- Target 3Personal loan
Debt snowball targets the smallest balance first, which can create earlier payoff milestones. Debt avalanche targets the highest APR first and generally reduces estimated interest when the same monthly payment budget is used. Both plans below use the same total monthly budget.
| Metric | Debt snowball | Debt avalanche | Difference |
|---|---|---|---|
| Debt-free date | April 2027 | April 2027 | Same month |
| Time to repay | 1 year, 4 months | 1 year, 4 months | No difference |
| Total paid | £10,269 | £10,269 | No difference |
| Total interest | £1,069 | £1,069 | No difference |
| Accounts cleared in first 12 months | 2 | 2 | No difference |
With the figures entered, the debt snowball plan costs about the same in interest as debt avalanche and finishes in the same month as it. Debt avalanche targets the highest APR first; debt snowball targets the smallest balance first.
This schedule is an illustration using monthly interest and fixed minimum payments. Your lender’s actual balance may differ.
| Debt | Starting balance | Estimated payoff |
|---|---|---|
| Store card | £1,200 | April 2026 |
| Credit card | £3,000 | October 2026 |
| Personal loan | £5,000 | April 2027 |
How the debt snowball method works
The debt snowball method focuses on your smallest debt balance first. You keep making the required minimum payment on every debt, then put any money left from your monthly repayment budget toward the smallest balance. When it is cleared, you roll that payment into the next-smallest debt.
This can create earlier payoff milestones and help build momentum. If reducing estimated interest is your main priority, compare your result with debt avalanche, which targets the highest APR first.
- Make the required minimum payment on every open debt.
- Use all remaining budget as an extra payment on the open debt with the smallest balance.
- When that debt is paid off, roll the freed payment into the next-smallest balance.
- Continue until every debt is cleared.
How to use this calculator
- Pick your currency at the top of the calculator. It changes formatting only, not the maths.
- Enter the total amount you can pay toward all debts each month. Include every required minimum payment plus any extra you can afford.
- Add each debt with its name, current balance, interest rate (APR) and required minimum monthly payment. Use Add another debt for more, up to 20, or load a worked plan with Use example debts.
- Read the payoff order, estimated debt-free date and the side-by-side comparison with debt avalanche.
Results update as you type. The plan assumes payments start in the current month, which is stated above the results.
How this calculator works
This calculator uses a monthly repayment model. It converts each annual percentage rate (APR) into a monthly rate, adds estimated interest to each outstanding balance, applies the required minimum payments and then puts the rest of your monthly budget toward the smallest remaining balance.
- APR — the annual percentage rate you enter for a debt (24% → a 2% monthly rate)
- Each month: add the interest, pay every minimum, then spend what is left on the smallest-balance debt
- When a debt clears, its freed payment rolls into the next-smallest balance the same month
- For equal balances, the higher APR is targeted first, then the order debts were entered
For example, an APR of 24% is modelled as a monthly rate of 2% (24% ÷ 12). With the example debts — a £3,000 card at 29.9%, a £1,200 store card at 34.9% and a £5,000 loan at 9.9% — and a £650 monthly budget, the £300 of minimums are paid first and the remaining £350 goes to the store card, because it has the smallest balance.
What does this calculator assume?
- Interest is modelled monthly and is added before the payment is applied.
- You keep making the fixed minimum payment entered on every open debt.
- Any remaining payment budget is directed to the open debt with the smallest balance.
- When a debt is cleared, unused payment money is immediately applied to the next-smallest balance.
- For equal balances, the calculator targets the higher APR first; if these are also equal, it uses the order debts were entered.
- The debt avalanche comparison uses the same payment budget but targets the highest APR first.
- Actual lender balances can differ because lenders may calculate interest daily, use statement dates, alter minimum payments, apply fees, change interest rates, or have specific settlement and early-repayment rules.
- The calculator does not model lender fees, penalty charges, early repayment charges, payment holidays, rate changes, promotional offers, lender-specific percentage minimum-payment rules or settlement offers.
How does the snowball versus avalanche comparison work?
The comparison runs a second, separate plan using exactly the same debts, APRs, minimum payments, start month and total monthly budget. The only change is the target rule: debt avalanche puts the extra payment toward the highest-APR debt instead of the smallest balance. Because both plans receive the same total monthly payment, the interest and time differences shown are like-for-like. They are only displayed when both plans clear every debt within the calculator’s 100-year illustration limit.
Debt avalanche generally produces the lower estimated interest cost. Debt snowball can clear individual accounts sooner, which some people find easier to stick with. The right plan is the one you can keep following.
Important information
Important: This calculator is an educational planning tool, not financial or debt advice. It cannot reproduce a lender’s exact statement balance, daily interest, fees or contractual payment rules, and the payoff date and interest figures are estimates based on the figures you enter.
Use it for planning repayments on non-priority debts such as credit cards, overdrafts, store cards and personal loans. If you are behind on rent or mortgage payments, council tax, energy bills, court fines or other essential bills, deal with those first. If you are struggling to pay, contact your creditors as soon as possible. Free, confidential debt advice may be available from StepChange, National Debtline and Citizens Advice.