How long will it take to pay off your debt?
List each debt with its balance, interest rate and minimum payment, then enter what you can pay in total each month. The calculator pays every minimum, puts the rest toward one target debt and rolls each paid-off debt's payment into the next. With $15,500 across two cards and a car loan, an $800 monthly budget clears everything in 22 months and costs $1,569 in interest using the avalanche method.
The avalanche method targets the highest interest rate first. In the example, that's the card at 22.9%. It always costs the least interest, because every spare dollar goes where interest grows fastest. The snowball method targets the smallest balance first. It clears the $1,500 card in month 4, compared with month 14 under avalanche, but costs $1,633 in interest, $64 more.
The method matters less than the budget. Raising the budget from $800 to $1,200 a month in the example clears the debts in 14 months instead of 22 and cuts interest to $972. Paying only the minimums of $450 a month takes 45 months and costs $4,405. Every extra dollar shortens the timeline, so look for spending you can redirect.
Pick the method you'll stick with. Research on debt repayment suggests that quick wins keep some people going, which is the case for snowball. If you're motivated by the numbers, avalanche saves the most. Either way, stop adding new debt, keep a small emergency fund so a surprise bill doesn't go on a card, and check whether a lower-rate consolidation loan or balance transfer would cut the interest further.