Debt Avalanche Calculator
Pay off highest APR first — math-optimal payoff order saves the most interest.
Avalanche method (highest APR first)
47 months
Mathematically optimal — pays the least interest. Snowball is psychologically easier; avalanche is dollar-optimal.
The debt avalanche is a payoff strategy that orders your debts from the highest APR to the lowest and puts every extra dollar toward the most expensive debt first.
You pay the minimum on all debts, then attack the highest-rate balance until it is cleared, then move to the next-highest rate. This targets the interest that is costing you the most.
Of the common payoff orders, the avalanche pays the least total interest and usually finishes fastest, which makes it the math-optimal choice for anyone who can stay disciplined.
How this calculator works
List every debt, make the minimum payment on all of them, then send every spare dollar to the debt with the highest APR, regardless of balance size. When that debt is cleared, roll its full payment into the debt with the next-highest APR. Because you always attack the most expensive interest first, this order mathematically minimizes the total interest paid and usually the payoff time. The calculator compounds each debt at its own rate and totals the interest so you can compare it against the snowball order.
Assumptions and data behind the estimate
The tool orders your debts from highest APR to lowest, compounds each at its own monthly rate (APR divided by 12), pays every minimum, and sends all extra money to the highest-rate debt before moving to the next, which mathematically minimizes total interest. It assumes fixed minimums, a constant total payment, and no new borrowing. Variable rates and issuer-specific minimum formulas can shift the ideal order over time, so the results are planning estimates, not financial advice.
What affects the number
- Order is set by APR, highest first, regardless of how large or small the balance is.
- It minimizes total interest and typically finishes at least as fast as any other order.
- The first debt can take a while if the highest-APR balance is large, so early motivation is weaker.
- Keep every other account current on its minimum while you focus extra on the top-rate debt.
- Variable APRs can change the ideal order, so recheck rates if the prime rate moves or a promo expires.
- The dollar savings over the snowball grow with the spread between your highest and lowest APRs.
Frequently asked questions
What is the debt avalanche method?
You list debts from highest APR to lowest, pay the minimum on all of them, and send every extra dollar to the highest-rate debt first. When it is gone, you roll that payment into the next-highest rate. Attacking the most expensive interest first minimizes what you pay overall.
Why does the avalanche save the most interest?
Interest cost is driven by rate, so eliminating your highest-APR balance first stops the fastest-growing charges sooner. Every dollar removed from a high-rate debt saves more than the same dollar on a low-rate debt. That is why the avalanche is the mathematically optimal order.
When should I choose snowball over avalanche?
Choose the snowball if you need visible early wins to stay motivated, or if your smallest balances are also fairly high rate, in which case the two orders nearly match. Choose the avalanche if your main goal is to pay the least interest and you can stay disciplined without quick payoffs. Both require keeping all minimums current.
Do changing interest rates affect the avalanche order?
Yes. Variable APRs can move with the prime rate, and promotional rates expire, either of which can change which debt is most expensive. If a rate changes materially, re-sort your debts by current APR and aim your extra payment at the new top.
Sources and references
This calculator provides general estimates for educational purposes only and is not financial advice. Your actual costs and credit outcomes depend on your specific card terms, issuer, and situation.