Adding $100 a Month to Debt Payoff: What It Actually Saves

Most of the debt advice online wants you to pick a team. Snowball or avalanche. Smallest balance or highest rate. People argue about it for hours.

Prefer to watch?

Debt Battle: Snowball vs. Avalanche Method - Which Wins?

Brian walks through it on video.

Here's what I've found running the numbers: the ordering matters, but it matters less than one boring thing nobody argues about — whether you send an extra hundred dollars a month. On a realistic set of debts, that extra $100 saved more than the choice between the two famous methods did. Let me show you.

The setup: four debts, $37,000, $889 a month

This is a sample household, but the shape of it will look familiar. Four debts:

Total debt: about $37,000. Total minimum payments: $889 a month. The longest debt runs 87 months, which is a little over seven years. If this household just pays what's due each month and never reorders anything, the interest bill comes out around $16,000.

Sixteen thousand dollars. For borrowing money they already spent.

Step one: stop letting freed-up payments disappear

Here's the thing almost everybody gets wrong. When that $2,000 credit card finally hits zero at month 25, the $100 payment stops. And most people just... keep the $100. It gets absorbed into groceries and gas and you never see it again.

Both the snowball and the avalanche are built on the opposite instinct. When a debt dies, its payment doesn't go free — it gets drafted onto the next debt. The $100 lands on the $164 loan, so that loan now gets $264 a month. When that one clears, $264 rolls onto the next. Your total outflow stays $889 the whole time. You never feel a change in your budget. But the debts start falling over faster and faster.

This is the whole trick. Everything else is detail.

Step two: pick an order (snowball or avalanche)

Snowball — smallest balance first

List the debts $2,000, $6,000, $8,000, $21,000. Attack the smallest. On this example, the snowball cut the interest from about $16,000 down to about $13,000 and the timeline from 87 months to 57 months. That's $2,779 saved and 30 fewer payments — nearly three years — without adding a single extra dollar.

Avalanche — highest rate first

Same four debts, different order: the 25% card goes first, then the 20% card, then down the line by rate. Same $889 a month, same rolling of freed-up payments. The avalanche saved about $3,000 and also 30 payments.

So who wins?

The avalanche, by roughly $300 to $400 in interest, with basically the same payoff date. Mathematically it should win — you're killing the most expensive debt first. Think of it this way: if you're standing at the bottom of a hill and you see a snowball coming down one side and an avalanche coming down the other, you know which one does more damage faster.

But $300 over five years is about five dollars a month. That's the real size of this famous argument. If seeing a debt vanish early is what keeps you going, take the snowball and don't feel bad about it. A plan you follow beats a plan you abandon in month four.

Step three: the $100 that beats both methods

Now the part that actually moved the needle.

Most payoff calculators have a box for an extra monthly amount. On this same example, changing $889 to $989 — one extra hundred dollars a month — saved roughly another $3,000 in interest and another 9 months.

Read that again. The $100 did as much as the snowball did. It did more than choosing avalanche over snowball did, by a factor of about ten.

Stack them together and you get the real plan:

• Roll the freed-up payments: ~$3,000 and 30 months
• Order by interest rate instead of balance: ~$300 more
• Add $100 a month: ~$3,000 more and 9 more months

Combined, you're looking at roughly $6,000 of interest you don't pay and well over three years you don't spend in debt. On $37,000 of debt. With one hundred extra dollars a month.

Where does the $100 come from?

I'm not going to pretend $100 is lying around for everyone. But it's a smaller number than people assume once they go looking. Streaming services you forgot about. A phone plan you've never renegotiated. Eating out twice less per week. Cash back rewards sitting in an account doing nothing. The point isn't permanent deprivation — it's a temporary squeeze that ends when the debt does. There's more on finding it in cutting expenses temporarily.

And here's the part people miss: once your debts are gone, that $989 a month is yours. Every month. Forever. That's the actual prize.

How to run your own numbers in ten minutes

1. Write down every debt with three things: balance, interest rate, minimum payment. Pull them off your statements, not from memory.
2. Open the debt snowball calculator and enter them smallest balance first. Hit calculate. Write down the interest saved and payments saved.
3. Now enter the exact same debts highest interest rate first — that's all it takes to turn it into an avalanche. Or use the debt avalanche calculator directly. Calculate again and compare.
4. Put a number in the extra monthly amount box. Try $50. Try $100. Watch what happens.
5. Scroll down to the month-by-month schedule. It tells you exactly how much to send each debt each month. Print it or screenshot it.

That schedule is the whole plan. You don't have to think again — you just follow the rows.

A few honest caveats

You can't lower your principal with a calculator. You owe what you owe. What you can change is interest and time, and those two are worth thousands.

Also, don't add an extra payment you can't sustain. If $200 a month means you're back on the credit card by March, you've gone backwards. Pick a number you'd still be sending in month eighteen when you're bored of the whole thing. Boring and sustainable wins.

And if one of your debts is a high-rate card, look at whether you can cut the rate before you attack it — a 0% balance transfer changes the math on the avalanche entirely.

Bottom line

Snowball versus avalanche is a real question with a small answer: avalanche usually wins, by a few hundred dollars. Take whichever one you'll actually finish.

The big answer is the extra hundred. On a $37,000 example, rolling payments plus $100 a month turned roughly $16,000 of interest and 87 months into something far smaller and far shorter. Run your own numbers on the free calculators, then start. If you want the full walkthrough, the get out of debt course takes it step by step, and building a payoff plan that actually works covers what to do when the plan hits a rough month.