Free Debt Payoff Calculator — Snowball vs Avalanche
November 2, 2026 · 3 min read · By the DollarWise team
How it works
Enter up to three debts — each with a balance, annual interest rate and minimum monthly payment — plus any extra you can put toward debt each month. The calculator simulates both popular strategies month by month: the avalanche method puts extra money toward the highest-interest debt first, while the snowball method clears the smallest balance first for quick psychological wins. It shows total interest paid, months to freedom and how much each strategy saves.
## How the math works
Each month, every remaining balance accrues one month of interest (annual rate ÷ 12). You then pay the required minimum on every active debt, and every rupee left over goes to the top-priority debt. When a debt clears, its minimum payment is freed up and rolls into the next one — this "rollover" is what makes both methods accelerate over time:
**Monthly interest = balance × (annual rate ÷ 1200)**
**Avalanche priority:** sort debts by interest rate, highest first — minimises total interest paid.
**Snowball priority:** sort debts by balance, smallest first — clears a debt quickly for psychological momentum, usually at the cost of slightly more total interest.
The simulation runs month by month until every balance hits zero (capped at 1,200 months to catch debts that can never be paid off at the given minimum).
## Everyday uses
- **Choosing a strategy:** see the exact interest cost difference before committing to avalanche (math-optimal) or snowball (motivation-optimal).
- **Extra-payment test:** find out how much sooner you are debt-free if you put an extra Rs. 2,000–5,000 per month in.
- **Balance-transfer check:** compare what happens if you move a high-rate balance to a lower-rate card before running the simulation.
## Frequently asked questions
### Which method should I actually use?
If you are confident you will stick to the plan, avalanche is mathematically optimal and saves the most interest. If you have struggled to stay motivated in the past, snowball's quick first-win can be worth the small extra interest cost. Many people use a hybrid: snowball for the first debt, then switch to avalanche once the habit sticks.
### Why does the calculator say my debt "may never clear"?
If your minimum monthly payment is less than the interest accruing each month, the balance grows instead of shrinking — the simulation caps at 1,200 months to flag this. Increase your monthly payment, ask your lender about a lower rate, or seek credit counselling.
### Does this include late fees and penalty interest?
No — it assumes you always pay on time at the stated rate. Late fees, penalty APRs and rate changes will increase your real cost. Always pay at least the minimum by the due date to avoid extra charges.