Debt Snowball Calculator

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 the Debt Avalanche Calculator, which targets the highest APR first.

1. Make the required minimum payment on every open debt.
2. Use all remaining budget as an extra payment on the open debt with the smallest balance.
3. When that debt is paid off, roll the freed payment into the next-smallest balance.
4. Continue until every debt is cleared.

How to use this calculator

1. Pick your currency at the top of the calculator. It changes formatting only, not the maths.
2. Enter the total amount you can pay toward all debts each month. Include every required minimum payment plus any extra you can afford.
3. 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.
4. 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.

What do I need to enter?

• Currency — changes the symbol and number formatting only; amounts are not converted.
• Total amount you can pay toward all debts each month — your whole monthly budget, minimums included. It must be greater than 0.
• Debt name — a label of up to 50 characters, used in the payoff order and schedule.
• Current balance — what you owe on that debt today. It must be greater than 0.
• Interest rate (APR) — the annual rate on that debt, 0 or more. It is divided by 12 for the monthly interest.
• Required minimum monthly payment — the least you must pay on that debt each month. It must be greater than 0.

What do the results show?

• Estimated debt-free date — the month the last debt is cleared under the snowball plan.
• Time to debt-free and estimated total interest — how long the plan takes and the interest it adds.
• Accounts cleared — how many debts are gone in the first year (or in total, if the plan finishes sooner).
• Initial extra payment — the budget left after the minimums, which goes to the smallest balance first.
• Your payoff order — each debt ranked by target, with its APR, starting balance and the month it clears.
• Snowball vs avalanche, Balance chart and Payoff schedule — the two methods side by side, total debt falling over time, and the month each debt is cleared.

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.

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.

Frequently asked questions