Debt Payoff Calculator
Compare avalanche vs snowball, see your debt-free date, and find out exactly how much interest you’ll save by adding extra payments.
Build your plan
Edit your debts below — the chart updates instantly.
How this calculator works ↓New to a term? Money terms explained.
Your debts
Mortgages are intentionally excluded from this calculator. They're long-term, low-interest, and tax-advantaged — usually better to keep paying as scheduled and direct extra cash toward higher-rate consumer debt (or invest it). If you want to model paying yours off aggressively, add it manually with the + Add debt button, or use the dedicated Mortgage Analyzer instead.
Your plan
Plan around…Directing your extra — to —
Your payoff plan
Per-debt progress & payoff order
Avalanche vs Snowball
Elimination timeline
Amortization snapshot
Showing every 3rd month| Month | Date | Remaining | Interest paid |
|---|
Tools that pair well with this plan
- High-yield savings for your found-money buffer
- 0% balance transfer cards for high-APR credit card debt
- Debt consolidation lenders for lower fixed rates
How this calculator works
Each debt you enter has a balance, an APR (the yearly interest rate, including any fees) and a minimum payment (the least the lender accepts each month). The calculator runs a month-by-month simulation, and every month does the same four things in order:
- Adds interest. Each balance grows by one month of interest: the APR divided by 12. A $6,800 card at 22.9% APR adds about $130 of interest in the first month.
- Pays every minimum. Each debt that still has a balance receives its minimum payment.
- Sends the extra to one target. Whatever is left of your monthly total goes to a single debt. Under avalanche that is the highest-APR debt; under snowball it is the smallest balance. If the target is paid off mid-month, the leftover cascades to the next target.
- Rolls freed payments forward. Once a debt is gone, its minimum stays in your monthly total, so the next target gets attacked harder. This rollover is what makes both methods speed up over time.
The simulation runs until every balance is zero (or for 50 years, at which point it reports that the plan never finishes). "Interest saved vs minimums" compares your plan against paying only the minimums with no extra and no strategy. The avalanche vs snowball panel runs both strategies on the same debts and budget so you can see the dollar difference between them.
In target debt-free date mode the calculator searches for the smallest extra payment that reaches zero by your date, then rounds it up to the nearest $25.
Assumptions and where they come from
| Assumption | Default | Source / note |
|---|---|---|
| Interest compounding | Monthly, at APR ÷ 12, on the current balance | Standard for credit cards and installment loans (loans repaid in fixed monthly amounts); real statements may charge interest daily instead, which differs by a few dollars over a payoff. |
| Payment timing | Interest is added first, then payments are applied | A conservative ordering: it never understates interest. |
| Rates | Fixed for the whole payoff | Variable-rate cards move with the prime rate (the base rate banks charge their best customers); re-run the plan if your APR changes. |
| Fees and new charges | None | Late fees, annual fees and new spending are not modelled. The plan assumes you stop adding to the balances. |
| Default credit card APR | 22.9% | In line with the Federal Reserve's average APR on cards that carry a balance: 22.15% in the second quarter of 2026 (G.19 consumer credit release). |
| Default auto loan APR | 7.2% | Roughly the Federal Reserve's reported rate on 60-month new-car loans at commercial banks (G.19, ~7%). |
| Default student loan APR | 6.5% | Rounded from the 6.52% fixed rate on new federal undergraduate loans for the 2026–27 school year; graduate loans carry 8.07%, and loans taken out in earlier years often have lower fixed rates (Federal Student Aid). Enter your own. |
| Mortgages | Excluded from the defaults | Long-term, lower-rate and usually tax-treated differently; add one manually if you want to model it. |
Assumptions last reviewed: October 2026.
Frequently asked questions
Which saves more money, avalanche or snowball?
Avalanche always pays the same or less total interest, because it targets the most expensive balance first. The calculator shows the exact gap for your debts in the avalanche vs snowball panel. When your rates are close together the difference is often small; when one debt is far above the others it can be large.
Then why would anyone choose snowball?
Snowball clears the smallest balances first, so you see accounts hit zero sooner. For some people that early progress is what keeps the plan going. The math favours avalanche; the calculator lets you see how much you would give up for the faster early wins.
What does "interest saved vs minimums" mean?
It compares your plan with a baseline where you pay only each debt's minimum every month, with no extra payment and no strategy. The difference in total interest is what your extra payment and payoff order are earning you.
Why does the calculator warn that a balance will keep growing?
When a debt's minimum payment is smaller than one month of its interest, the balance rises even though you are paying. Increase that minimum, add extra, or check that the APR you entered is right.
How does target date mode find the required extra?
It runs the same simulation repeatedly with different extra amounts until it finds the smallest one that clears every balance by your chosen month, then rounds up to the nearest $25 so the number is easy to budget.
Does the plan account for new charges or fees?
No. It assumes the balances you enter are the balances you pay off, with no new spending, late fees or annual fees. If you keep using a card, its real payoff will take longer than the projection.
This calculator is educational. It is not financial, tax, investment or legal advice. The assumptions are simplified; check them against your own situation or a licensed professional before acting on a result. See the Terms of Use.