The debt avalanche method is a mathematically optimal debt repayment strategy where you make minimum payments on all debts except the one with the highest interest rate, which receives all your extra money. Once the highest-rate debt is paid off, its payment cascades to the next highest rate, accelerating your payoff.

The key advantage of the avalanche method is that it minimizes the total interest you pay over the entire payoff period. Because high-interest debt accumulates charges fastest, eliminating it first reduces the total cost of your debt more efficiently than any other ordering strategy.

The trade-off is that the highest-rate debt may also have the largest balance, which means it can take longer to see your first debt eliminated. Some people find this demotivating compared to the snowball method, which provides quicker wins. If you are disciplined and motivated by saving money, the avalanche method is the best choice for minimizing total interest paid.