Debt Payoff Calculator
Find your exact debt-free date. Compare avalanche vs snowball strategies and see how much interest you can save.
A $10,000 card at the live 20.9% APR paying a fixed $200/month takes 119 months (~9.9 years) and $13,707 in interest. Doubling to $400/month cuts that to 34 months and $3,244.
20.9%
Live FRED commercial-bank average credit card APR (Q3 2026) — the rate the card row opens at by default
$13,707
Interest on $10,000 at 20.9% paying a fixed $200/mo — vs just $3,244 if you pay $400/mo
$6,471
Interest saved on the default two-debt plan by adding $200/mo and using avalanche — 76 months sooner
Two strategies. One goal: debt freedom.
The right approach depends on your psychology as much as the math.
Avalanche: the math-optimal method
Target your highest-rate debt first. Every dollar applied to a 22% APR card does more work than any dollar applied to a 6% car loan. Over years, this difference in interest compounds massively in your favour.
Snowball: the psychology-driven method
Small wins matter. Eliminating a debt completely triggers a dopamine response that keeps motivation high. Studies show many people who use the snowball method complete their debt payoff — even if they pay slightly more total interest.
The freed-payment snowball effect
When you eliminate one debt, that minimum payment doesn't go back into daily spending — it attacks the next debt. This growing 'snowball' of freed payments accelerates payoff dramatically as you progress. The last few debts get eliminated very quickly.
Example scenario
The same $10,000 debt — what your payment level changes
One $10,000 balance at the live 20.9% APR. The only thing that changes is the fixed monthly payment — and it changes everything. (Calculator simulation, minimum-only mode.)
| Balance | APR | Fixed payment | Time to pay off | Total interest |
|---|---|---|---|---|
| $10,000 | 20.9% | $200/mo | 119 mo (~9.9 yr) | $13,707 |
| $10,000 | 20.9% | $300/mo | 51 mo (~4.3 yr) | $5,096 |
| $10,000 | 20.9% | $400/mo | 34 mo (~2.8 yr) | $3,244 |
| $10,000 | 20.9% | $500/mo | 25 mo (~2.1 yr) | $2,401 |
Going from $200 to $400 a month more than triples your speed and cuts interest from $13,707 to $3,244 — a $10,463 swing on the same balance. That is the entire game: the higher and steadier your payment, the less of your money the lender keeps.
How does monthly interest work on credit cards?
Each month, your lender charges interest as Balance × (APR ÷ 12). On a $10,000 balance at 20.9% APR that's about $174 in the first month alone — so a $200 payment only knocks ~$26 off the balance. Raise the payment to $400 and ~$226 goes to principal every month, which is why the payoff time collapses.
How the Debt Payoff Calculator Works
Formula
Monthly interest = Balance × (APR / 12 / 100)
Principal paid = Payment − Monthly interest
Avalanche: sort active debts by interest rate (highest first)
Snowball: sort active debts by balance (lowest first)
Freed minimum: when a debt reaches $0, its minimum rolls into the
priority debt's payment next month (on top of your extra payment).
Minimum-only baseline does NOT roll freed payments.
Interest saved = Minimum-only total interest − Strategy total interest
Worked example — default plan (card $5,000 @ live 20.9% / $100 min,
car $12,000 @ 6.5% / $220 min), +$200 extra, avalanche:
Debt-free in 43 months (February 2030) · $2,645 interest
vs minimum-only 119 months / $9,116 → saves $6,471 and 76 months.Add your debts
Enter each debt: name, balance, interest rate, and minimum payment.
Choose a strategy
Avalanche saves the most money. Snowball provides the most motivation.
Set extra payments
Even $50/month extra makes a dramatic difference on high-interest debt.
Add a lump sum
Got a tax refund or bonus? Apply it immediately for maximum interest savings.
See your debt-free date
The exact month and year you'll be completely debt-free, with interest saved.
This calculator runs a full month-by-month simulation for both your chosen strategy and a minimum-only baseline, so you can see exactly what you save. The credit-card row opens at the live FRED commercial-bank average APR (~20.9%, refreshed automatically) so your starting point reflects today's real rate. The burn-down chart shows your declining balance over time.
The 'freed minimum' mechanic is key: every time you eliminate one debt, that payment doesn't disappear — it's added to the attack on the next debt. This is why the final debts vanish so fast, and why starting is the hardest and most important step. Note that minimums here are fixed dollar amounts; real card minimums often shrink with the balance, which is precisely why they can trap people in 20+ year payoffs.
Frequently Asked Questions
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