Debt Snowball vs. Avalanche Payoff Planner

Compare the debt snowball and avalanche payoff strategies side by side for up to 4 debts. See your debt-free date, total interest, and savings.

Mathematical Audit

Debt Snowball vs Avalanche Formula

Both strategies simulate your debts month by month. Each month, interest accrues on every balance, then you pay the minimum on every debt. Any extra money — plus the minimum payments from debts you've already paid off — is funneled entirely into one 'focus' debt until it reaches zero, then moves to the next.

Monthly Interest = Current Balance × (APR ÷ 12)
Debt Snowball: focus extra payments on the debt with the SMALLEST current balance first
Debt Avalanche: focus extra payments on the debt with the HIGHEST interest rate (APR) first
Once a debt reaches $0, its minimum payment rolls into the extra-payment pool for the next focus debt
Total Interest = Sum of all monthly interest charges until every balance reaches $0

Both methods use the exact same total monthly payment (sum of all minimum payments plus your extra payment) and always reach $0 in the same or fewer months as the avalanche method, which is mathematically guaranteed to minimize total interest. The snowball method often wins psychologically by clearing small debts first for quick motivational wins.

Operational Guide

How to Use the Debt Snowball vs Avalanche Planner

1

List your debts

Enter the current balance, APR, and minimum monthly payment for each debt (credit cards, loans, etc.) — up to 4 debts.

2

Enter your extra monthly payment

Input any additional amount you can put toward debt beyond the minimums each month.

3

Calculate

The planner simulates both the snowball (smallest balance first) and avalanche (highest APR first) strategies.

4

Compare the results

Review the months to debt-free, total interest paid, and payoff order for each method side by side.

5

Choose your strategy

Pick avalanche to save the most money, or snowball if you need quick wins to stay motivated — then save or share your plan.

Real-World Scenario Example

"Someone has a $5,000 credit card at 22% APR ($150 min), a $12,000 auto loan at 6% APR ($250 min), and a $3,000 store card at 18% APR ($90 min), and can put an extra $200/month toward debt."

Inputs

debt1Balance:5000
debt1Apr:22
debt1MinPayment:150
debt2Balance:12000
debt2Apr:6
debt2MinPayment:250
debt3Balance:3000
debt3Apr:18
debt3MinPayment:90
debt4Balance:0
debt4Apr:0
debt4MinPayment:0
extraMonthlyPayment:200

Result

Both methods take 34 months to become debt-free. The snowball method (store card, then credit card, then auto loan) costs $3,071 in total interest, while the avalanche method (credit card, then store card, then auto loan) costs $2,933 — saving $138 with no change in payoff time.

Important Disclaimer

This calculator provides estimates for educational purposes only and does not constitute financial advice. Actual interest charges depend on your lenders' compounding methods, fees, and any changes to your balances, rates, or payments over time.