Debt snowball vs avalanche: which is better, and how to build the spreadsheet

Updated 2026-10-20 · Plainsheet guides

If you have several debts (a couple of credit cards, a car loan, a personal loan, maybe a student loan), the hardest part usually isn't the math. It's knowing which debt gets your extra money this month. The two best-known answers are the debt snowball and the debt avalanche. This guide explains both in plain language, works through an example with real numbers, and shows you how to build a free debt payoff spreadsheet in Google Sheets or Excel so you can compare them for your own debts.

The shared rule: minimums on everything, extra on one

Both methods start the same way. You decide on one fixed monthly amount you can put toward debt, for example $900. Every debt gets its minimum payment, so you never miss one. Whatever is left after the minimums is your "extra" payment, and all of it goes to one target debt. When the target is paid off, its minimum payment doesn't go back into your spending. It gets added to the extra and rolls onto the next target. That roll-over is why the payment grows over time like a snowball rolling downhill.

The only difference between the two methods is which debt is the target.

• Snowball: target the smallest balance first, regardless of interest rate.
• Avalanche: target the highest interest rate (APR) first, regardless of balance.

A worked example

Say you have $900 a month for debt and these four debts:

The minimums add up to $525, so the extra is $375 a month.

Snowball order: store card ($650), personal loan ($3,200), Visa ($4,800), car ($9,500). The store card is gone in about two months. That first win shows up fast, and plenty of people find it's what keeps them going.

Avalanche order: store card (26%), Visa (22%), personal loan (11%), car (6.5%). The store card happens to be first here too, but then the avalanche goes after the Visa instead of the personal loan. Because the Visa charges twice the interest, the avalanche usually comes out a little cheaper in total. In examples like this one the difference is often tens to a few hundred dollars, and the debt-free date may move by only a month or two.

That is the typical pattern. Avalanche saves the most money on paper. Snowball gives you quicker visible progress. When the debts have similar interest rates, the two plans come out nearly the same. When one large debt has a much higher rate than the rest, avalanche can save a lot more.

How to choose

• Choose avalanche if you are motivated by the total interest number and can stay on track even when the first payoff takes a while.
• Choose snowball if you've started and stopped before, or you have several small balances you could clear quickly.
• Use a hybrid if you like: knock out one or two tiny balances for momentum, then switch to avalanche.

The most important factor is not the method. It's paying the same total every month and not adding new debt. A spreadsheet makes that visible.

Build a free debt payoff spreadsheet in Google Sheets

Step 1: the debt list

On a tab called Debts, make these columns: Name (A), Balance (B), APR % (C), Minimum (D). Put one debt per row in rows 2–9. In a separate cell, say G1, enter your total monthly debt budget (e.g. 900).

Step 2: the payoff order

For snowball, rank by balance, smallest first: =RANK(B2,$B$2:$B$9,1). For avalanche, rank by APR, highest first: =RANK(C2,$C$2:$C$9,0). Put both in columns E and F so you can compare them.

Step 3: the extra amount

In G2: =G1-SUM(D2:D9). If this is negative, your budget doesn't cover the minimums. Fix that first, by cutting spending, adding income, or talking to the lender about hardship options.

Step 4: the month-by-month schedule

Make a second tab, Schedule, with one row per debt and one column per month. Each month, each balance becomes:

=MAX(0, previous_balance * (1 + APR/12) - payment)

For a non-target debt, the payment is its minimum. For the target debt, it's the minimum plus the extra. When a debt reaches zero, add its minimum to the extra for the following month. You can do this by hand once a month, which takes about five minutes, or build helper columns that work it out automatically.

Step 5: the summary

Add a row that sums all balances per month, then put a line chart on it. The point where the line reaches zero is your debt-free month. Total interest is the sum of all payments minus the starting balances.

Common mistakes

• Forgetting interest. A balance that only drops by the payment amount will make your projection look too good.
• Changing the monthly total. Decide your budget once and only change it on purpose.
• No buffer. Without a small emergency fund, one surprise bill lands back on a card. Many people keep a starter fund of $500–$1,000 before going all-in.
• Never updating. Once a month, copy the real balances from your statements over the projection.
• Ignoring 0% promo deadlines. If a card's 0% period ends soon, its real APR is about to jump. Plan for the rate you'll actually pay.

Want it done for you?

The building takes an evening. If you'd rather skip it, the Plainsheet Debt Payoff Planner ($9) has everything above built in for up to 8 debts. Switch between Snowball and Avalanche from a dropdown and you'll see the payoff order, the payoff month for each debt, your debt-free date, and total interest. It works in Google Sheets and Excel. To find money for the extra payment, start with the free monthly budget sheet or the paycheck budgeting guide.

General information, not financial advice. Check lender terms before you change your payments.

FAQ

Is the debt snowball or avalanche faster?

Avalanche is usually slightly faster and cheaper because it pays the highest-interest debt first. Snowball gives you earlier wins. With similar interest rates the two plans end within a month or two of each other.

Can I do a debt snowball in Google Sheets for free?

Yes. List each debt's balance, APR and minimum, rank them by balance, and project each month with balance × (1 + APR/12) − payment, rolling paid-off minimums onto the next debt.

Should I save an emergency fund before paying off debt?

Many people keep a small starter fund, often $500 to $1,000, so a surprise expense doesn't go back on a credit card while they pay down debt.

Does the debt snowball work for student loans and car loans too?

Yes. Any debt with a balance, an interest rate and a minimum payment can go in the list. Large, low-rate loans such as mortgages are often left out of the snowball and handled separately, because paying them early has less impact than clearing high-interest cards. Federal student loans may also have income-driven or forgiveness options that change the math, so check those before you pay extra.

What if my minimum payments are more than I can afford?

Then a payoff plan can't start yet, and the first job is getting your cash flow positive. Look at your budget for cuts, ask lenders about hardship programs or lower rates, and consider a nonprofit credit counseling agency, which can sometimes negotiate a debt management plan. A spreadsheet still helps here, because it shows lenders and counselors exactly where you stand.

Should I use a balance transfer or consolidation loan?

Either can lower your interest cost if the new rate is clearly lower, the fees are small, and you stop using the old cards. Put the new loan in your spreadsheet as a single debt and compare the total interest against your current plan. If the promotional rate ends before you can clear the balance, plan around the rate you'll pay afterwards.

How often should I update my debt payoff spreadsheet?

Once a month, after your statements arrive. Replace the projected balances with the real ones, check that the target debt is still right, and look at the debt-free date. Fifteen minutes a month keeps the plan honest and shows you real progress, which is the best motivation there is.

← All guides