How this is worked out
Both schedules are walked month by month, since neither has a closed-form solution.
The minimum-payment schedule recalculates the payment each month as the greater of the issuer's dollar floor and a percentage of the current balance plus that month's interest. Because the balance falls, the payment falls, and each smaller payment clears less principal than the one before.
Two conventions exist for the minimum and the difference is not cosmetic. A minimum of "a percentage of the balance plus that month's interest" always reduces the balance. A flat percentage of the balance may not: at a 20–25% APR, 2% of the balance is barely above the month's interest, so the balance decays so slowly that the payoff runs past this calculator's sixty-year horizon. The calculator says which of the two has happened rather than reporting both as failure.
The fixed-payment schedule holds the amount steady. Interest for the month is balance × APR ÷ 12; everything above that reduces the principal. A constant payment therefore clears an accelerating share of the balance.
For several debts, avalanche and snowball are simulated in full: every debt receives its minimum, and the remainder of the budget goes entirely to one target — the highest rate, or the smallest balance — with the freed payment rolling onto the next debt as each clears.
A worked example
- Balance / APR
- $6,000 at 20.99%
- Minimum payment rule
- 1% of balance plus interest, $10 floor
- First minimum payment
- $164.95
- Minimum only — time to clear
- 28 years 2 months
- Minimum only — interest paid
- $10,078
- Fixed $300 a month — time
- 25 months
- Fixed $300 a month — interest
- $1,449
The minimum shrinks with the balance, which is why it never ends
Your minimum payment is a percentage of what you owe. Pay it down and the percentage is taken of a smaller number, so the payment falls. Each smaller payment covers the interest first and reduces the principal by a little less than the last one did.
On $6,000 at 20.99% with a minimum of 1% of the balance plus interest, the first payment is $164.95 — of which $104.95 is interest and $60 reaches the balance. Twenty-eight years and $10,078 in interest later, the card is finally clear. The same balance at a fixed $300 a month is gone in twenty-five months for $1,449.
The first payment differs by $135. Everything else about the outcome differs because one number holds still while the other retreats.
Your statement is required to tell you this
Federal cost of credit disclosure regulations require a credit card statement to show how long it will take to clear the balance making only minimum payments. It is a single line and it is easy to miss, but it is the same calculation this page performs.
Quebec is the exception worth knowing about. Under amendments to the Consumer Protection Act, the minimum payment on cards issued there rises annually — it has been climbing by half a percentage point each year toward a 5% floor. Cardholders in Quebec therefore clear balances substantially faster than the rest of the country, by legislation rather than by choice.
If your card was issued in Quebec, raise the minimum percentage field above to match your current statement.
Avalanche costs less; snowball gets finished
With several debts, avalanche targets the highest rate and always costs less in interest — that falls out of the arithmetic and is not a preference. Snowball targets the smallest balance and clears one debt sooner, which is why more people complete it.
The calculator simulates both and reports the real gap for your figures. Across a typical mix of a bank card, a retail card at 29.99% and a car loan, the difference is often several hundred dollars while snowball clears its first debt within a few months.
Retail store cards in Canada frequently carry rates near 30%, which usually settles the argument: when one debt is at 29.99% and the rest are under 10%, avalanche is worth the wait.
Balance transfers, lines of credit, and free help
Promotional balance transfer offers exist here too, typically at a low rate rather than 0%, with a transfer fee of 1% to 3%. The arithmetic is the same: divide the balance by the number of promotional months and pay that, or you have bought a delay rather than a solution.
A secured line of credit or a HELOC will carry a far lower rate, but it converts unsecured debt into debt against your home. That is a real trade rather than a free improvement, and it should be treated as one.
If no realistic payment clears the balance, speak to a non-profit credit counselling agency accredited by Credit Counselling Canada, or to a Licensed Insolvency Trustee — the only professionals legally able to file a consumer proposal or bankruptcy, and required to give you a free initial consultation. Debt settlement companies charging large upfront fees are neither, and several provinces have had to legislate specifically against them.
Assumptions and sources
- Payoff schedules
- Both schedules walked month by month. Verified in tools/test/finance.mjs against independently calculated payoff tables.
- Minimum payment disclosure
- Federal cost of borrowing regulations require credit card statements to state the time to clear the balance on minimum payments. checked 2026-08
- Quebec minimum payment
- Consumer Protection Act amendments phasing the minimum payment up toward 5% for cards issued in Quebec. checked 2026-08
- Insolvency options
- Consumer proposals and bankruptcies may only be filed by a Licensed Insolvency Trustee, regulated by the Office of the Superintendent of Bankruptcy. checked 2026-08