Debt snowball calculator: smallest first, paid in full
The snowball pays your smallest balance first, then rolls that payment into the next debt. Below, a realistic three-debt household ($15,500 at $340 of minimums) becomes debt-free in 35 months with a $200 monthly extra, instead of 67. Move the slider and the ledger re-posts.
Debt strategy planner · snowball method · free, always
The example plan, at $200 extra a month =
35 months to debt-free
with $2,866.12 of total interest.
3 debts · $540 monthly budget ($340 minimums + $200 extra)
| Order | Debt | Balance | APR | Paid in full |
|---|---|---|---|---|
| 1 | Store card | $1,200.00 | 24% | Month 6 |
| 2 | Credit card | $4,800.00 | 21% | Month 21 |
| 3 | Personal loan | $9,500.00 | 9% | Month 35 |
How the rollover works, month by month
Each month the plan pays every minimum first: $30 on the store card, $120 on the credit card, $190 on the loan. Whatever is left of the $540 budget attacks the store card. In month 6 the store card hits zero, and from month 7 its old $30 minimum rolls into the credit card. In month 21 the credit card dies and its $320 minimum joins the loan. The last 14 months are a single $540 payment against the loan. Nothing extra was conjured; the plan just kept every freed dollar inside it.
Try it with your extra payment
| Extra/month | Debt-free | Total interest |
|---|---|---|
| $0 (minimums only) | 67 months | $7,126.14 |
| $200 | 35 months | $2,866.12 |
| $250 | 31 months | $2,537.77 |
Why smallest-first beats highest-rate-first for most people
The avalanche (highest rate first) is mathematically cheaper, and on these exact example debts it would land on the same 35 months and the same interest, because the smallest balance happens to carry the highest rate. That convergence is a lesson in itself: when your rates line up with your balances, the strategy question answers itself. The snowball's real edge is behavioral. Research by Gal and McShane (2012) found that closing an account predicts finishing the whole payoff plan, while the dollar size of the win does not. The snowball manufactures that first closed account as fast as possible: the store card here dies in month 6, giving the plan its first win 15 months before the avalanche-style ordering would deliver one.
The rule that makes it work is the rollover. Every dollar that was a minimum stays in the fight after the debt dies. The plan fails the way diets fail: a paid-off card that "frees" $30 for spending is not the snowball, it is the plan being abandoned. Keep every freed minimum inside the budget and the math above is what happens.
Educational estimates, not financial advice. Interest accrues monthly at balance × APR ÷ 12, rounded to the cent; minimums and rates are assumed constant. Talk to a licensed professional before acting on these figures.
Common questions
Is the debt snowball better than the avalanche?
It depends on which you will finish. The avalanche costs less interest; the snowball clears an account sooner, and research finds that first closed account predicts sticking with the plan. If your highest-rate debt is also your smallest, the two methods are identical.
What if my budget only covers the minimums?
Then the plan runs at the pace of the minimums: 67 months and $7,126.14 of interest in the example above. The slider shows what even $25 extra buys. If the minimums do not fit the budget, the plan cannot start until something gives.
Do I include all my debts in the snowball?
Include every unsecured debt with interest: cards, store cards, personal loans. A mortgage is usually excluded because its size would swallow the plan's momentum; pay it on its own schedule.
Next from the ledger
How long to pay off credit card debt: sees what the minimum-only trap does to a single card
Debt snowball vs avalanche: runs both strategies on the same four debts, side by side
Balance transfer calculator: checks whether a 0% offer beats grinding it out