Free debt snowball spreadsheet

Type your debts in. It tells you the month you'll be debt-free, what the interest costs you, and how much sooner you'd finish than by paying minimums. Works in Excel, Numbers and Google Sheets.

What you get

• Your debt-free date, as an actual month, at the top of the plan.
• Snowball or avalanche from a dropdown. Switch it and watch the date and the interest move.
• A month-by-month schedule for up to ten debts and twenty-five years, showing what you paid, what interest was added, and what's left.
• The comparison that matters: how many months and how many dollars this plan saves against paying only the minimums.
• Live formulas. Nothing is hard-coded, so it keeps working as your balances change.

How to use it

1. Open the Your debts tab and type over the example rows. Name, balance, interest rate, minimum payment.
2. Put the total you can pay each month toward all your debt in the yellow box. Minimums included.
3. Pick Snowball or Avalanche from the dropdown.
4. Open Your plan. Your debt-free date is the big green month at the top.

Snowball or avalanche?

Avalanche always costs less interest, because it attacks the highest rate first. Snowball closes an account sooner, and a closed account is what makes people keep going. The gap in total interest is usually smaller than people expect.

The spreadsheet shows you the real number for your own debts rather than the general argument, so change the dropdown and compare.

How the math works

Each month, interest is added first, at your annual rate divided by twelve. Then every debt receives its minimum payment. Whatever is left of your budget goes to the first debt in your attack order until it reaches zero, and then rolls onto the next one. That rolling payment is the snowball.

The attack order is fixed at the start from the balances you typed, which is how the method is actually taught: list them once, attack them in that order. The order column on the debts tab shows you exactly what it decided.

If a minimum doesn't cover the interest

Then that balance grows even while you pay it, and the spreadsheet will show it climbing. That is not a bug in the sheet, it is the actual situation, and it is the case where attacking by interest rate matters most.

Is it exact?

It is an estimate, and so is every payoff planner. Real statement interest moves a little depending on when inside the cycle your payment lands. The month it gives you is reliable; the last few dollars of interest are not.