Debt Payoff Calculator
Find how many months it takes to pay off a debt at a fixed monthly payment and the total interest, with guidance on snowball vs avalanche.
| Name | Balance $ | APR % | Min $/mo |
|---|
Avalanche vs Snowball
Avalanche, snowball, and which one actually finishes
There are two credible ways to order multiple debts. Avalanche pays the minimum on everything and throws every spare pound at the highest interest rate first. It is mathematically optimal — it always costs the least and finishes soonest. Snowball targets the smallest balance first regardless of rate. It costs more, sometimes considerably, and it works better for a lot of people anyway.
The reason is that debt payoff fails from abandonment far more often than from arithmetic. Snowball clears an entire account early, which produces a visible win and one fewer payment to track, and that momentum keeps people going. A method you finish beats a method you optimise and quit. If the rate spread is narrow, the cost of choosing snowball is small; if one debt is at 24% and another at 4%, avalanche's advantage is large enough to be worth the patience.
Whichever you pick, the mechanism is the same: keep the total payment fixed as balances clear. When one debt finishes, roll its payment onto the next rather than absorbing it into spending. That rolling amount is what accelerates the schedule — without it, both methods collapse into paying minimums forever, which on a credit card at 20% can take decades and cost more than the original balance.
Frequently asked questions
What is the Debt Avalanche method?
The Debt Avalanche method prioritizes paying off debts with the highest interest rates first to minimize total interest paid.
How long will it take to pay off my debt?
It depends on the balance, the rate and - most of all - how much above the minimum you pay. Because interest accrues on the remaining balance, every extra amount shortens the term more than proportionally. Even small consistent overpayments compress the timeline noticeably.
Does paying extra each month really help that much?
Yes, because the entire overpayment reduces principal, which reduces every subsequent interest charge. On a long, high-rate debt, an extra 10% on the payment can cut years off the term. Confirm with the lender that overpayments are applied to principal rather than held as a prepaid future instalment.
Should I pay off debt or invest?
Compare the debt's interest rate to a realistic after-tax investment return. Paying off 20% credit card debt is a guaranteed 20% return that no investment reliably matches. Below roughly 5-6%, particularly for tax-deductible debt, investing often wins - but always capture an employer retirement match first, since that is an immediate 50-100% return.