Debt Payoff Calculator
Avalanche pays highest-rate first (cheapest); snowball pays smallest-balance first (most motivating). Enter your real debts below and see exactly what each strategy costs you in time and interest.
Debt-free in (avalanche)
—
- Total debt today
- $0
- Avalanche — total interest
- $0
- Snowball — total interest
- $0
- Snowball takes
- —
- Avalanche saves you
- $0
Assumes fixed APRs and a constant total monthly budget (minimums + extra).
Strategy comparison
Your payoff order
| Debt | Balance | APR | Avalanche order | Snowball order |
|---|
How to use this calculator
- List up to four debts with their current balance, APR, and minimum monthly payment (leave unused rows at zero).
- Enter the extra amount you can put toward debt each month beyond the minimums.
- Compare the two strategy cards: total interest and payoff date under avalanche vs. snowball.
- Follow the payoff order shown for your chosen method — and re-run the numbers whenever a debt dies.
How the simulation works
Each simulated month, every debt accrues interest at APR ÷ 12, receives its minimum payment, and one target debt receives all remaining budget. When a debt reaches zero, its minimum payment stays in the budget and rolls to the next target — the "snowball" effect both strategies share. The only difference is targeting order:
- Avalanche targets the highest APR first — mathematically optimal, minimizes interest.
- Snowball targets the smallest balance first — behaviorally optimal for many people, maximizes early wins.
With the default example ($21,500 across three debts, $300/month extra), avalanche finishes in 2 years 8 months with $4,168 of interest; snowball takes one month longer and costs $4,694 — avalanche saves about $526. That's a realistic picture: the methods usually land close, and the gap widens when large balances carry the highest rates.
Getting the inputs right
- Balance — today's payoff balance from your statement or app, not the original loan amount.
- APR — the purchase APR for cards (on statements); note that promotional 0% rates expire.
- Minimum — the fixed minimum from your statement. For cards whose minimum shrinks with the balance, using today's minimum is slightly conservative — you'll finish a touch sooner than shown.
Avalanche vs. snowball examples with real debts
Three debt situations, both strategies simulated by this calculator. Click one to load it, then swap in your real balances.
- Two cards + a bill
$10,400 across three debts, $250 extra
Cards of $6,000 at 22% and $3,500 at 26%, plus a $900 interest-free medical bill.
Avalanche: debt-free in 2y 1m, $2,458 interest. Snowball: 2y 2m, $2,809 — but its first cleared debt lands in month 3. Avalanche saves $351.
Load this scenario in the calculator → - Big card, small loan
When avalanche clearly wins
A $9,000 card at 27%, a $5,000 loan at 10%, a $1,200 bill at 0% — $350 extra per month.
Avalanche: 2y 2m and $3,023. Snowball: 2y 4m and $4,549. The big high-rate balance makes avalanche worth $1,526.
Load this scenario in the calculator → - Graduate with a card
When both methods agree
A $22,000 student loan at 6.8% and a $4,500 card at 24% — the card is both smallest and highest-rate.
Both strategies: 3y 4m, $3,547 interest — identical, because both target the card first. Run yours to see which camp you are in.
Load this scenario in the calculator →
Frequently asked questions
What is the debt avalanche method?
Pay minimums on every debt, then send every spare dollar to the debt with the highest interest rate. When it's gone, roll its entire payment into the next-highest rate. Avalanche minimizes total interest — it is the mathematically fastest payoff order.
What is the debt snowball method?
Pay minimums on everything, then attack the smallest balance first regardless of rate. Each cleared debt is a quick, visible win that frees its minimum payment for the next target. It usually costs somewhat more interest, but behavioral research finds the early wins help people actually finish.
Which method should I choose?
Run your real debts through the calculator above and look at the gap. If avalanche saves only a small amount (common when balances and rates align), pick whichever keeps you motivated. If the gap is large — high-rate cards with big balances — avalanche's savings are hard to ignore. A popular hybrid: one quick small-balance win first, then strict avalanche.
Should I pay off debt or invest?
Compare interest rates to expected returns. Paying off a 24% credit card is a guaranteed 24% return — nothing in investing reliably beats that. Below roughly 6–7% APR (many mortgages, some student loans), investing alongside minimum payments becomes reasonable. In between, it's a judgment call about certainty versus upside.
Does debt consolidation help?
It can, if the consolidation rate is genuinely lower and you don't re-run the cards you just cleared. A consolidation loan simplifies to one payment; the risk is treating freed-up credit as new spending room. The math tool here still applies — model the consolidated loan as a single debt.
What happens if I can only afford the minimums?
You'll still get debt-free eventually on amortizing loans, but credit cards with minimums near the interest charge can take decades. If the calculator warns your budget barely covers interest, prioritize any extra income toward the highest-rate card — even $25/month changes the trajectory.