Debt Snowball vs. Avalanche Calculator
A free debt payoff calculator comparing the snowball and avalanche methods. Add your debts and see your payoff date, total interest, and what an extra payment saves.
Who it's for: Anyone paying off more than one debt who wants a realistic payoff date
There are two sensible ways to attack multiple debts, and people argue about them constantly. The snowball clears your smallest balance first. The avalanche clears your highest interest rate first. This calculator runs both against your actual numbers so you can stop guessing which one is worth it.
Debt Snowball vs. Avalanche Calculator
List your debts, add whatever extra you can spare, and see the payoff date each method gives you.
Anything above the minimums — even $25 moves the date.
Debt-free in
2 yr 10 mo
Paying $530/month in total
Your extra $150/month buys you
39 months earlier · $2,841 less interest
Both methods cost about the same here — pick whichever keeps you going.
Payoff order: Store card → Credit card → Car loan
Estimates only, for education. Your own rates, fees, and circumstances will differ.
What the calculator is doing
Each month it charges interest on every balance, pays every minimum, then throws whatever is left of your extra payment at one target debt. When a debt clears, its minimum rolls into the extra payment — that rolling effect is the "snowball", and it is why payoff accelerates rather than staying linear.
The only difference between the two methods is which debt gets targeted:
| Targets first | Strongest argument | |
|---|---|---|
| Snowball | Smallest balance | You clear a whole debt early, which keeps you going |
| Avalanche | Highest APR | You pay less interest overall |
Which one should you pick?
Run both and look at the gap. That is the honest answer, and it is why the calculator shows you what switching would cost.
For most people the difference is smaller than expected — often a few hundred dollars across several years. If the avalanche saves you $80, the snowball is probably the better choice, because a method you abandon in month four saves nothing at all. If the avalanche saves you $2,000, that is real money and worth the slower start.
The one case where avalanche clearly wins is when you have a large balance at a very high rate — a maxed store card at 27% sitting alongside a modest car loan at 6%. There, targeting the small car loan first lets the expensive debt keep compounding.
Why the extra payment matters more than the method
The calculator shows a line for what your extra payment buys you, and it is usually the biggest number on the page. Moving from $0 extra to $150 extra typically cuts years off the schedule. Switching methods might cut months.
Put differently: how much you overpay matters more than which debt you overpay. If you only have energy for one decision, make it finding an extra $50 rather than optimising the order.
Finding the extra payment
- Run a subscription audit and cancel what you do not use
- Redirect one regular takeaway or delivery each week
- Put any refund, bonus, or side income straight at the target debt
- Ask your card provider for a lower rate — it costs nothing to ask
- Check whether a 0% balance transfer would beat your current APR after fees
Reading the "not at this rate" result
If the calculator says you will not clear the debt, it means your minimum payments are barely covering the interest being charged. The balance is treading water or growing.
This is a genuinely difficult situation and not one a calculator solves. It is worth speaking to a non-profit debt advice service — they are free, they do not sell you anything, and they can often negotiate rates or arrange a plan that stops interest accruing. Do not wait until you have missed payments to make that call.
What this calculator does not include
- Fees — annual fees, late fees, and balance transfer fees are not modelled.
- Variable rates — it assumes your APR stays put, which credit card rates often do not.
- Promotional periods — a 0% intro rate that expires mid-schedule will change the result.
- Minimum payments that shrink — many cards calculate the minimum as a percentage of the balance, so it falls as you pay down. The calculator holds your minimum steady, which makes it slightly conservative.
Treat the payoff date as a good planning estimate, not a promise.
Read the full guide
For a step-by-step walkthrough of setting up a payoff plan and sticking with it, read our guide on the debt snowball method.
When to be careful
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