Debt Snowball Calculator
Months and interest to clear three debts by paying the smallest balance first.
What it does
The debt snowball is a payoff plan built for momentum. You keep paying the minimum on every account, and every spare dollar goes to the smallest balance. Once that balance is gone, the money you were paying on it joins the extra payment and rolls onto the next smallest balance, growing like a snowball as it rolls downhill.
This tool runs the plan month by month on up to three debts. You enter each balance, its annual rate, and its minimum, plus the extra amount you can add each month. It returns the months to debt free, the interest paid, and the order in which debts clear.
Interest is charged every month on the balance, so a month of growth is added before the payment is applied. The snowball reduces the number of debts you owe rather than the total interest, which is why it can cost more than the avalanche method that targets the highest rate first.
People who have been stuck on minimum payments often quit because progress is invisible. Clearing a small balance quickly proves the plan works, and that early win is the point of the method. The cost is measured in interest, not in motivation.
If two debts are close in size, the smaller one clears first as the name implies. If a rate is very high, the avalanche method will usually save more. Many people run the snowball for motivation but pick the highest rate when the balances are similar. This page models the snowball exactly as described.
How to use
- Enter the extra amount you can add each month.
- Enter each debt balance, annual rate, and minimum.
- Leave a debt balance at 0 if you only have one or two.
- Press calculate to see the months, interest, and total paid.
- Read the payoff order to see which balance clears first.
- Raise the extra payment to see how much time and interest it saves.
Formula
- Balance
- Amount owed on each debt this month.
- Rate / 12
- Monthly interest rate from the annual percent.
- Extra
- Money above all minimums paid to the smallest balance.
The plan assumes fixed minimums and no new charges. In real life a minimum can fall as the balance drops, and new spending can raise a balance. Use the payment you actually make, and stop using the cards you are paying down.
Worked example
Example: $2,000, $5,000, and $9,000 debts with $150 extra
Debt A 2,000 at 22 percent, Debt B 5,000 at 18 percent, Debt C 9,000 at 15 percent, minimums 50, 100, and 180, extra 150.
- Every month the three balances grow by rate / 12 before payment.
- The minimums total 330, so 330 + 150 = 480 goes out each month.
- The smallest balance, Debt A, takes all of the extra and clears first.
- Debt B clears next with its minimum plus the 150 and the freed Debt A payment.
- Debt C finishes last. All three clear in 55 months, about 4 years and 7 months.
- Interest over the run is about 6,006.93 dollars, so total paid is about 22,006.93 dollars.
Reference table
| Point | Debt A | Debt B | Debt C |
|---|---|---|---|
| Start | 2,000 | 5,000 | 9,000 |
| Minimum each month | 50 | 100 | 180 |
| Clears | Around month 4 | Around month 22 | Around month 55 |
| Payment then rolls to | Debt B | Debt C | Done |
Limits
- Handles up to three debts. Combine smaller ones if you have more.
- Assumes fixed minimums and no new charges on any account.
- Ignores fees, late charges, and promotional rate changes.
- Rounds balances to the cent each month, so figures can differ slightly from a servicer.
Common mistakes
- Adding new charges to cards while paying them down.
- Forgetting a required minimum, which can trigger a fee and a higher rate.
- Giving up because the first debt is large. Order by size, not by feeling.
- Ignoring that a high rate on a big balance can cost more than the snowball saves.
- Skipping the emergency fund, so the next surprise goes back on a card.
Try it yourself
Quick checks. Answers sit tucked under each question.
One 1,000 dollar debt at 20 percent, minimum 25, with 300 extra?
It clears in 4 months with about 35.49 dollars of interest.
Which debt clears first in the example?
Debt A, the smallest balance at 2,000 dollars.
Does a larger extra payment change the order?
No. The smallest balance still goes first. It only shortens the time and cuts interest.
Questions
Snowball or avalanche?
Snowball clears small balances first for motivation. Avalanche targets the highest rate and usually costs less interest.
Does the snowball save money?
Compared with minimums only, yes. Compared with the avalanche, not always, because it may leave a high rate running longer.
What if two debts are the same size?
The tool sorts by balance, and ties clear together in the same month.
Should I keep an emergency fund while paying debt?
Yes. A small buffer stops a surprise from adding a new balance.
Can I add a fourth debt?
This page takes three. Combine the two smallest into one line if you have more.
Do minimums stay the same?
Here they do. On real cards a minimum can fall as the balance drops, which can change the timing.