EmpireSheets

Debt Payoff Calculator

Avalanche against snowball, run side by side, with the real cost of choosing either.

What this does

List what you owe, the rate on each, and what you can put toward debt each month. This runs both standard methods to completion and shows the gap between them in dollars and in months, so the choice is made on a number rather than on an argument.

Why this one

Most payoff calculators pick a method for you and show one answer. This runs both, because the honest position is that avalanche always costs less and snowball is the one some people actually finish. Where the gap is forty dollars the argument is not worth having. Where it is four thousand, it is. You should be told which one you are looking at.

The formula

each month: interest  =  balance x annual rate / 12
pay every minimum, then put everything left on one debt
avalanche  =  highest rate first        snowball  =  smallest balance first

Published so you can check it. A calculator about money that will not show its working is asking to be trusted on the one thing you cannot verify.

Questions

Which method is better?
Avalanche always costs less in interest and is never slower, because it attacks the most expensive money first. Snowball clears an account sooner, which some people need in order to keep going. The tool shows you what that costs so you can decide with the number in front of you.
Why does it refuse to run sometimes?
If the monthly amount is below the total of your minimum payments, no plan is possible without missing one. Missed payments change the arithmetic in ways this cannot model, so it says so rather than projecting something untrue.
Does it account for new spending on the cards?
No. It assumes you stop adding to the balances. Continuing to spend on a card you are paying down is the single most common reason a plan like this does not survive contact with reality.