Debt Payoff Calculator (Snowball & Avalanche)

How to use

1. Replace the three starter rows with your own figures, and press + Add a debt for another row. A blank row is ignored until it holds a balance.
2. Give each row a Name you'll recognise in the clearing months, then fill in Balance, APR % and Min a month.
3. Type what you can genuinely spare above the minimums into Extra a month. The line under it adds up what goes out each month in all.
4. Choose Smallest first or Highest rate first under Order of attack. Highest rate first is chosen when the page opens.
5. Read the answer at the top as you type; there is nothing to press. Each row's tag says the month that debt clears.
6. Press Show payoff schedule under the chart for the month-by-month table. Copy the plan puts it on your clipboard, and Share the plan copies a link that brings back every row.

About this tool

The hard part of clearing several balances is never the arithmetic. It's deciding which one to hit first. Hand this debt payoff calculator your balances, rates and minimum payments, add whatever you can spare on top, and it walks month by month until the last balance reaches zero. Out comes the number of months to debt-free, the calendar month it lands in, the interest paid along the way, and beside each debt the month it clears.

Smallest first, the snowball, sorts by balance and goes after the smallest one, whatever it costs you in interest. Highest rate first, the avalanche, sorts by rate and goes after the priciest. You pick one under Order of attack, and the page quietly runs the other as well, so the cost of the choice sits right under the answer in money and months.

Underneath, both run the same engine. Each month every debt gets its minimum, everything left over lands on the one target debt, and the moment a target clears, its minimum joins the pool chasing the next one. What you pay out never rises. What lands on the front debt climbs steadily, which is why the last debt often disappears in a few months after the first one took years.

There is one case where no plan works: if your combined payments are no bigger than the interest your debts throw off each month, the balances only grow. The answer then reads never, says how much more a month it would take to start falling, and any single debt whose minimum loses to its own interest is flagged in its row. When the numbers do work, a chart draws both orders' balances month by month, and the payoff schedule and a CSV sit underneath it.

What the starting numbers do

The page opens on three debts: a store card of 800 at 9.9% paying 25 a month, a Visa of 6,400 at 26.99% paying 160, and a car loan of 9,800 at 7.25% paying 305, with 150 extra on top and highest rate first chosen. Everything is gone in 33 months for 3,529.88 of interest. Switch to smallest first and the date does not move, but the interest rises to 3,797.37, which makes the order worth 267.49 on these figures.

Now set Extra a month to 0. The same debts take 50 months and 7,056.50 of interest, and the two orders land 76 cents apart, because with nothing spare there is nothing to aim. The ladder under the form shows the step between: 50 more a month already saves 1,631.36.

Good to know

• Rates are fixed for the whole run. A 0% promo that expires next spring, a variable APR, or a card you keep spending on will all drift away from this plan.
• Interest is charged once a month on the whole balance. Most credit cards use a daily periodic rate instead, so a real statement lands a little differently.
• Amounts carry no currency symbol. Enter whatever you actually bank in and keep every row in the same one.
• It is arithmetic on what you typed, not debt advice. A balance transfer, a hardship plan or a settlement offer can beat any payment order shown here, and those are worth asking a counsellor about.