📌 How to Use This Calculator
- Debt name: Anything that helps you tell them apart - "Visa", "store card", "car loan". It only appears in the results.
- Balance: What you owe on that debt today, not the original amount borrowed.
- APR: The annual interest rate on your statement. If a card is in a 0% promotional period, enter 0 and remember to re-run this when the promotion ends.
- Minimum: The smallest payment the lender will accept each month. Both methods pay this on every debt, every month.
- Total monthly budget: Everything you can put towards debt combined. The calculator pays all the minimums first and sends whatever is left to the target debt.
The Only Real Difference Between the Two Methods
Both methods do exactly the same thing with all but one of your debts: pay the minimum, every month, without fail. Everything left over in your budget goes to a single target debt. When that target clears, its whole payment rolls onto the next one. The snowball effect that both methods are named after is really this rolling - your total monthly payment never changes, but the amount hitting each remaining debt grows every time one disappears.
The methods differ on one question only: which debt is the target?
| Debt Avalanche | Debt Snowball | |
|---|---|---|
| Target | Highest interest rate first | Smallest balance first |
| Optimises for | Money. Always the cheaper of the two, sometimes by a lot | Momentum. First debt disappears sooner, often much sooner |
| Feels like | Slow at first if your highest-rate debt is also your largest | Fast early wins, then progressively bigger targets |
| Main risk | Months of effort with nothing visibly cleared, which is where people give up | Paying more interest than you needed to |
Why the Gap Between Them Varies So Much
Most articles quote a single figure for how much the avalanche saves. That figure is meaningless, because the gap depends entirely on the shape of your debts, and it ranges from almost nothing to thousands of dollars.
When the two methods are nearly identical
If all your debts sit within a few percentage points of each other - say three cards at 19%, 21% and 22% - then the order barely matters. You are paying roughly the same rate whichever one you attack. In cases like this the avalanche might save you a couple of hundred dollars over several years, and the snowball's earlier first win is arguably worth more than the difference.
When the avalanche wins decisively
If one debt carries a dramatically higher rate than the rest - a 27% store card sitting alongside a 6% personal loan - then targeting anything other than the store card is expensive. The gap widens further when that high-rate debt also happens to be one of the larger balances, because the snowball would leave it untouched for years while it quietly compounds.
The question is not "which method is better in general". It is "how big is the gap for my specific debts", and that is a number only your own figures can answer.
Choosing Between Cheaper and More Likely to Finish
Once the calculator has given you the gap, the decision becomes straightforward and honest. You are choosing between a cheaper plan and a plan you are more likely to complete.
If the avalanche saves you a meaningful amount, take the avalanche and find your motivation somewhere other than crossing debts off a list - a chart on the fridge, a monthly balance check, a standing order you never have to think about. If the gap is small, the snowball is a perfectly rational choice, because a method you follow for three years beats a mathematically superior method you abandon in month seven.
There is also a middle path that suits a lot of people: clear one genuinely tiny balance first, purely to get it off the board, then switch to strict avalanche order for everything that remains. You pay a small premium for the early win and keep almost all of the interest saving.
Things This Calculator Assumes
Every model simplifies. These are the assumptions behind the numbers above, so you know where reality might differ:
- You add no new debt. Putting new spending on a card you are trying to clear changes everything, and no calculator can model a moving target.
- Interest rates stay fixed. Variable rates move, and promotional 0% periods end. Re-run the numbers when yours change.
- Minimum payments stay fixed. Real card minimums usually fall as the balance falls. This makes the calculator slightly conservative, which is the safer direction to be wrong in.
- Payments arrive on time, every month. Late fees and penalty APRs are not modelled and would make both methods worse.
- No fees are included beyond interest - no annual fees, balance transfer fees or overlimit charges.
What to Do After You Have Your Answer
- Write down the order. The payoff sequence in the results is the whole plan. Put it somewhere you will see it.
- Automate the minimums. Standing orders on every debt remove the possibility of a missed payment wrecking the plan.
- Send the extra manually. Paying the target debt by hand each month keeps you connected to the progress, which is the part that keeps people going.
- Re-run this every few months. Rates change, balances change, and your budget may grow. The optimal order can shift.
- Check a single card in detail. Our credit card payoff calculator builds a full month-by-month amortization schedule for one balance, which pairs well with the plan above.
Frequently Asked Questions
What is the difference between the debt avalanche and the debt snowball?
Both pay the minimum on every debt and send all spare money to one target. The avalanche targets the highest interest rate first, which minimises total interest. The snowball targets the smallest balance first, which clears individual debts sooner and produces visible progress earlier.
Which method is better?
The avalanche always costs less, because paying the highest rate first is mathematically optimal. Whether that saving is worth having depends on how large it is for your particular debts, which is exactly what this calculator measures. If the gap is small, choose the method you are more likely to finish.
How much does the avalanche actually save?
It varies enormously. With debts at similar rates the two methods can finish within a few dollars of each other. With one debt at a far higher rate, the avalanche can save hundreds or thousands. Enter your real numbers rather than trusting a general figure from an article.
Do I keep paying the minimum on my other debts?
Yes, always. Missing a minimum triggers late fees and can damage your credit score, which costs far more than any interest you might save. Only the money left over after every minimum is paid goes to the target debt.
What happens when one debt is paid off?
Its entire payment rolls onto the next target, on top of that debt's own minimum. Your total monthly outgoing stays the same the whole way through, which is why both methods speed up as they progress and why the last debts clear far faster than the first.
What if I cannot cover all my minimum payments?
Neither method works in that situation, and the calculator will tell you so rather than producing a misleading plan. This is a point to seek help rather than a maths problem to solve - a non-profit credit counselling service can discuss options such as a debt management plan or negotiated rates with your lenders.
Should I include my mortgage or student loans?
You can, but most people leave long-term low-rate debt out and focus on expensive short-term debt. If you include a mortgage, its very large balance and low rate will sit at the bottom of the avalanche order and the top of the snowball order, which distorts the comparison.