Free online calculator
Debt payoff calculator
Snowball or avalanche payoff plan.
Debt payoff calculator
Snowball vs avalanche — compare strategies and total interest.
Applied above all minimums
⚠ Interest warnings
Payoff order
Add debts to see payoff order.
How to use this calculator
- 1
Add your debts
Click "Add debt" and enter each debt's name, current balance, APR, and minimum monthly payment.
- 2
Enter extra monthly payment
Type any extra amount you can put toward debt each month above all minimums.
- 3
Compare strategies
The results panel shows payoff months and total interest for both snowball and avalanche.
- 4
See the savings delta
A highlighted row shows how much interest avalanche saves over snowball (or vice versa).
- 5
Check payoff order
Expand "Payoff order" to see which debt is eliminated in which month for each strategy.
Formula
Each month: interest accrues on each balance, minimums are applied, then the entire extra pool (plus freed minimums from paid-off debts) goes to the focus debt.
Snowball focus: debt with the lowest remaining balance.
Avalanche focus: debt with the highest APR.
Rolling payment: when debt N is paid off, its minimum joins the extra pool for debt N+1.
Worked example
3 debts, $200 extra/mo:
Credit card $4,500 @ 22% APR, $90 min. Car loan $8,000 @ 7% APR, $180 min. Student loan $12,000 @ 5% APR, $130 min.
Snowball targets the $4,500 card first. Avalanche also targets the card first (highest APR). In this case both strategies agree on order, so interest savings are minimal.
FAQ
What is the snowball method? +
The debt snowball method targets the smallest balance first while paying minimums on all others. Once a debt is paid off, its minimum payment "snowballs" into the next smallest balance. It provides quick psychological wins.
What is the avalanche method? +
The debt avalanche method targets the highest interest rate first. It minimises total interest paid and is mathematically optimal, though it can feel slower if your highest-rate debt has a large balance.
What does "rolling payment" mean? +
When a debt is fully paid off, its former minimum payment is automatically redirected to the next focus debt. This accelerates payoff without requiring you to increase your total monthly outgoing.
Why does my balance show a warning? +
If the minimum payment on a debt is less than the monthly interest accruing on that balance, the balance will grow over time even while making payments. You should increase the minimum payment or add extra to that debt.
Is the extra payment applied on top of all minimums? +
Yes. The calculator first applies minimum payments to every debt, then directs the entire extra pool to the focus debt chosen by the selected strategy.
About this calculator
This debt payoff calculator runs a month-by-month simulation of both the snowball method (smallest balance first) and the avalanche method (highest interest rate first). It shows total interest paid, payoff timeline, and the order in which debts are eliminated — including how freed-up minimum payments roll into the next debt automatically.
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Track every debt payment in one place
Spendspace lets you log payments, watch balances drop, and stay on plan — download the free iOS app.
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