Debt Snowball vs Avalanche Calculator
With the monthly payment fixed, only the order changes. Avalanche attacks the highest rate first; snowball attacks the smallest balance first. Carrying 3,000,000 at 7% and 8,000,000 at 19% while paying 600,000 a month, avalanche finishes in 22 months with 1,426,801 of interest, snowball in 23 months with 2,010,110 — some 583,000 of interest riding on the order alone. Avalanche never loses on interest. Snowball sells itself on something else: a debt visibly disappearing early.
Your numbers
Interest difference
583,310
Highest rate first: months
22mo
Smallest balance first: months
23mo
Highest rate first: interest
1,426,801
Smallest balance first: interest
2,010,110
What it means
Highest rate first clears in 22 months; smallest balance first takes 23 months and 583310 more interest.
Formula
Interest difference = Smallest balance first: interest − Highest rate first: interest
Two debts only. With three or more the number of orderings grows and the result shifts. The debt not being attacked is assumed to be serviced at interest-only, so its balance holds — where the minimum payment exceeds the interest it really finishes sooner, and where it falls short the balance grows. Prepayment penalties, missed-payment records and rates that change mid-course are not in here.
What to enter
| Input | Default | Accepted range |
|---|---|---|
| First balanceThe principal still owed on the first debt. | 3,000,000 | 0 ~ 1,000,000,000,000 |
| First rate (%)The annual rate on the first debt. | 7 | 0 ~ 100 |
| Second balanceThe principal still owed on the second debt. | 8,000,000 | 0 ~ 1,000,000,000,000 |
| Second rate (%)The annual rate on the second debt. | 19 | 0 ~ 100 |
| Monthly paymentWhat you owe every month. | 600,000 | 0 and up |
Step by step
Quick reference table
Results when only First balance changes and everything else stays put.
| First balance | Interest difference | Highest rate first: months (mo) | Smallest balance first: months (mo) |
|---|---|---|---|
| 1,500,000 | 351,541 | 19 | 20 |
| 2,250,000 | 403,198 | 20 | 21 |
| 3,000,000 | 583,310 | 22 | 23 |
| 4,500,000 | 821,019 | 24 | 26 |
| 6,000,000 | 1,156,529 | 28 | 30 |
What each result means
| Result | At default values |
|---|---|
| Interest differenceThe interest riding on the order alone; highest-rate-first never loses on interest. | 583,310 |
| Highest rate first: months (mo)Months to clear both when the higher rate is attacked first. | 22 |
| Smallest balance first: months (mo)Months to clear both when the smaller balance is attacked first. | 23 |
| Highest rate first: interestTotal interest paid attacking the higher rate first. | 1,426,801 |
| Smallest balance first: interestTotal interest paid attacking the smaller balance first. | 2,010,110 |
Common mistakes
Two debts only. With three or more the number of orderings grows and the result shifts. The debt not being attacked is assumed to be serviced at interest-only, so its balance holds — where the minimum payment exceeds the interest it really finishes sooner, and where it falls short the balance grows. Prepayment penalties, missed-payment records and rates that change mid-course are not in here.
Glossary
- First balance
- The principal still owed on the first debt.
- First rate
- The annual rate on the first debt.
- Second balance
- The principal still owed on the second debt.
- Second rate
- The annual rate on the second debt.
- Monthly payment
- What you owe every month.
- Interest difference
- The interest riding on the order alone; highest-rate-first never loses on interest.
- Highest rate first: months
- Months to clear both when the higher rate is attacked first.
- Smallest balance first: months
- Months to clear both when the smaller balance is attacked first.
- Highest rate first: interest
- Total interest paid attacking the higher rate first.
- Smallest balance first: interest
- Total interest paid attacking the smaller balance first.
Frequently asked questions
Q. How is Debt Snowball vs Avalanche Calculator calculated?
Interest difference = Smallest balance first: interest − Highest rate first: interest — With the monthly payment fixed, only the order changes. Avalanche attacks the highest rate first; snowball attacks the smallest balance first. Carrying 3,000,000 at 7% and 8,000,000 at 19% while paying 600,000 a month, avalanche finishes in 22 months with 1,426,801 of interest, snowball in 23 months with 2,010,110 — some 583,000 of interest riding on the order alone. Avalanche never loses on interest. Snowball sells itself on something else: a debt visibly disappearing early.
Q. Can you walk through an example?
With First balance 3,000,000, First rate 7%, Second balance 8,000,000, Second rate 19%, Monthly payment 600,000, the answer is Interest difference 583,310.
Q. What do I need to enter?
Enter First balance, First rate, Second balance, Second rate, Monthly payment. The result recalculates as you type, and an empty box counts as zero.
Q. How much does the answer move if I change a number?
Changing only First balance moves the answer to First balance 1,500,000 → Interest difference 351,541 and First balance 6,000,000 → Interest difference 1,156,529. The table below lays out five steps.
Q. How are the numbers rounded?
Money is shown to the nearest whole unit, percentages to one decimal place and everything else to two. What you see is rounded; the calculation itself carries the unrounded value forward.
Q. Anything to watch out for?
Two debts only. With three or more the number of orderings grows and the result shifts. The debt not being attacked is assumed to be serviced at interest-only, so its balance holds — where the minimum payment exceeds the interest it really finishes sooner, and where it falls short the balance grows. Prepayment penalties, missed-payment records and rates that change mid-course are not in here.
Related calculators
Tax rates and interest conventions differ by country and product — check your contract for real transactions.