Debt Payoff Calculator
↻ Updated 2026List your debts and see how the snowball and avalanche methods compare — payoff time, total interest, and how much an extra payment saves. Everything runs in your browser.
Educational calculators — always consult a licensed professional before making financial decisions.
Runs entirely in your browser — nothing you enter is sent to us.How this works
How to read your snowball vs avalanche result
The two strategies are closer together than the internet suggests, and the extra payment matters far more than either. On the defaults, avalanche beats snowball by $540 over the whole payoff — while the $200 extra payment is worth $3,482. Pick the ordering you'll actually follow; the size of the budget is where the money is.
How the snowball and avalanche payoff orders are simulated
Both methods run the same engine and differ in one line: which debt gets the leftover money. The monthly budget is fixed at the sum of your minimums plus your extra payment, and it never falls. That constant budget is what makes either method work — as each debt clears, its freed-up minimum rolls onto the next target rather than leaking into your spending.
Avalanche sorts by APR, highest first, and is mathematically guaranteed to cost the least interest: every spare dollar is always retiring the most expensive dollar of debt available. Snowball sorts by balance, smallest first, which is by definition not the cheapest order — the case for it is behavioural, not arithmetic, and it's covered in the FAQs below.
budget = sum(minimums) + extra ← constant every month order = debts sorted by APR descending (avalanche) = debts sorted by balance ascending (snowball) repeat each month until every balance = 0: 1. each debt accrues: balance += balance × (APR ÷ 12) 2. pay each debt its minimum 3. pool = budget − minimums paid pour pool into the first debt in order until it's gone, then the next, and the next
- budget
- The fixed total you send to all debts each month — sum of minimums plus the extra — it stays constant as debts clear, which is the whole mechanism
- extra
- What you add on top of the minimums each month — the single input with the largest effect on both interest and payoff date
- minimums
- The minimum payment on each debt, as a fixed dollar amount — you enter these; the model never reduces them as balances fall, unlike a real card
- APR
- The annual rate on each debt, converted to monthly as APR ÷ 12 — assumed fixed for the life of the payoff — no promo expiries, no penalty repricing
- order
- The priority list the leftover pool is poured into — computed once from today's figures and never recomputed — see the limitations below
Step 3 is the part people miss. The extra payment isn't the only thing accelerating you — every minimum you free up gets redirected too. By the time the last debt is standing it's absorbing the entire budget, which is why the final balances fall so much faster than the first. The snowball's name describes this rolling effect, but both methods do it; they only disagree about the direction of travel.
To see the effect of the extra payment alone on a single loan, the extra payment calculator runs that comparison directly.
Worked examples
Example: $22,000 across three debts with a $200 extra payment
The calculator's defaults: a $6,000 card at 22.9% (minimum $150), a $12,000 car loan at 7.5% (minimum $320), and a $4,000 personal loan at 12% (minimum $110). The budget is $580 of minimums plus $200 extra — $780 a month, every month.
| Avalanche order22.9% → 12% → 7.5% | Card → personal loan → car |
| Snowball order$4,000 → $6,000 → $12,000 | Personal loan → card → car |
| Avalanche33 months | $3,650.56 · 2 yr 9 mo |
| Snowball34 months | $4,190.88 · 2 yr 10 mo |
| Avalanche advantageand one month sooner | $540.32 |
| Same debts, no extra paymentavalanche, extra set to $0 | $7,132.72 · 4 yr 3 mo |
Avalanche wins by $540.32 and one month — real, but modest against a $22,000 debt load. Now compare it to the other lever: dropping the extra payment to $0 costs $3,482.16 in extra interest and eighteen extra months. The $200 extra payment is worth roughly six and a half times more than the strategy choice. The argument people have online is about the smaller number.
Example: the same three debts with no extra payment at all
Drag the extra payment slider to $0. Nothing else changes — the budget is now just the $580 of minimums, still rolling from one debt to the next as each clears.
| Avalanche51 months | $7,132.72 · 4 yr 3 mo |
| Snowball51 months — identical payoff date | $7,135.21 · 4 yr 3 mo |
| Avalanche advantageover four and a quarter years | $2.49 |
Two dollars and forty-nine cents. With no extra payment the ordering barely matters, because the minimums are large enough relative to the balances that each debt clears at nearly the same time either way — the rolling pool that the ordering controls is tiny. The strategy debate only has stakes once you have spare money to direct, and the more spare money you have, the more the ordering is worth. That's the honest shape of it: extra payment first, ordering second.
Frequently asked questions
Is the debt snowball or avalanche better?
Avalanche costs less, always. It's not a close question arithmetically — paying the highest APR first minimises interest by construction, and no ordering can beat it. On the defaults it saves $540.32 and finishes a month earlier.
The case for the snowball is that people finish it more often. Gal and McShane (Journal of Marketing Research, 2012) studied clients of a debt settlement firm and found that the fraction of accounts closed predicted eliminating the debt, while the dollar balance of what was closed did not — consistent with discrete completed tasks driving persistence. Kettle, Trudel, Blanchard and Häubl (Journal of Consumer Research, 2016) found across experiments and field data that concentrating repayment on one account, rather than spreading it, increased motivation and repayment.
Two honest caveats. Both papers measure persistence and account closure, not total interest — nobody disputes the avalanche is cheaper. And the 2012 study is observational, so people who close accounts may simply be the people who were going to get out of debt anyway. If the two orderings cost roughly the same for your debts — check by setting extra to $0 — the behavioural argument is free to take. If they're far apart, you're paying for the motivation.
How much extra should I pay on my debt each month?
This calculator won't tell you what to afford, but it will price the decision. Every $25 you add to the extra-payment slider is worth watching: on the defaults, moving from $0 to $200 cuts total interest from $7,132.72 to $3,650.56 and pulls the debt-free date in by eighteen months.
The return is front-loaded in an unintuitive way. The extra payment attacks the highest-APR debt in the avalanche, so the first dollars are earning your worst rate — 22.9% on the default card. That's the number to compare anything else you'd do with the money against.
Does the debt snowball work if all my debts have similar interest rates?
That's exactly the case where it's free. When APRs are close together, the ordering barely changes the interest, so you can take the behavioural benefit at almost no cost. The defaults here span 7.5% to 22.9% — a wide spread — and still only produce a $540 gap.
The reverse is where it gets expensive: a large balance at a very high APR alongside a small balance at a low one. The snowball would have you clear the cheap small debt while the expensive one compounds. Enter your real figures and read the two rows in the comparison panel — if the gap is small, pick the one you'll finish.
Why is my minimum payment not going down as I pay off debt?
On an installment loan — car, personal, student — it isn't supposed to. The payment is fixed for the whole term by the amortization schedule, and paying extra shortens the term rather than shrinking the payment. That's why the car loan's $320 in this model stays at $320 until it's gone.
Credit cards work the opposite way, and it's the reason minimum-only payoffs take so long: the minimum is a percentage of the balance, so it falls as you pay down, stretching the tail out indefinitely. This calculator treats every minimum as a fixed dollar amount, which is right for the loans and generous to the cards. The minimum payment calculator models the shrinking version properly.
Should I pay off debt or save first?
We publish the arithmetic on both sides rather than a rule. On the debt side, the return on clearing a balance is certain and equal to its APR — the default card here is 22.9%, tax-free and risk-free, which is a rate no ordinary investment offers with any reliability. On the savings side, the case is about liquidity, not return: money in a payoff can't be taken back out when the car breaks, and borrowing again at 22.9% undoes the gain.
The comparison shifts sharply with the rate. A 22.9% card and a 4% federal student loan are not the same decision, and this calculator's spread of APRs is a good place to see how differently the same dollar performs depending on where you point it.
Where this payoff plan is simpler than your actual debts
The simulation is exact for the model it runs. The model is a simplification in five ways that can move your real payoff date.
- The payoff order is frozen at today's figures — Both orderings are computed once, from the balances and APRs you enter now, and never recomputed. A real avalanche is unaffected by this — APR ranking rarely changes. A real snowball can diverge, because balances move: a debt that's second-smallest today may be smallest in six months.
- Minimums never shrink — You enter a fixed dollar minimum per debt and it holds until that debt is gone. Card issuers recalculate the minimum from the balance every cycle, so it falls as you progress — which makes a real card payoff slower than this shows, and makes the case for a fixed payment stronger than this page can.
- Fixed APRs, no promotional rates — Rates are constant for the whole payoff. No 0% intro period expiring, no variable rate tracking prime, no penalty APR after a late payment. If one of your debts is sitting on a promo rate about to end, this understates it.
- No fees, no new spending, and no test of affordability — Annual and late fees are absent, and every balance only ever falls — continuing to spend on a card you're paying down is the most common reason a real payoff misses its date. The budget is also assumed paid in full every month for the whole term. A plan that leaves no room for a $600 emergency tends to end with the emergency back on the card.
- ·Standard loan amortization formulas
Rates, brackets and limits here are checked against primary sources. If a number still looks off, email support@realmoneyiq.com and we'll review and fix it.
RealMoneyIQ provides free educational calculators, not financial, tax, investment or legal advice. Results are estimates based on the assumptions you enter and publicly published rates; your actual outcome will differ. Always confirm decisions with a licensed professional who knows your full situation.