What is the debt payoff calculator?
In short
Avalanche (highest APR first) saves the most interest; snowball (smallest balance first) delivers quicker wins that build momentum. On $20,000 of debt averaging 18% APR with $600/month minimum payments, avalanche saves roughly $2,800 in interest vs snowball. Adding just $100 extra per month to either method cuts payoff by 2–3 years. Both methods beat paying minimums only by thousands of dollars — the key is picking one and staying consistent.
This debt payoff calculator compares the avalanche and snowball payoff strategies, shows total interest, time to debt-free, and a month-by-month balance chart for each method.
How to use this calculator
- 1Enter each debt — name, current balance, annual interest rate, and minimum payment.
- 2Enter any extra monthly amount you can put toward debt above all minimums.
- 3Choose your preferred method (avalanche or snowball).
- 4Compare interest saved, total paid, and time to debt-free between methods.
The formula
- B
- — Current balance
- r
- — Monthly interest rate (APR ÷ 12)
- P
- — Payment (minimum + extra)
Worked example
The scenario
Credit card $5,000 at 22%, student loan $15,000 at 6%, car loan $8,000 at 7%, personal loan $3,000 at 12%. Extra: $200/month.
The result
Avalanche pays off in ~44 months with ~$5,800 total interest. Snowball pays off in ~46 months with ~$6,600 interest — about $800 more but gives faster early wins.
Common use cases
- Deciding between avalanche and snowball strategies
- Figuring out how much extra payment per month matters
- Planning a debt-free date
- Comparing multiple debt elimination scenarios
Limitations & assumptions
- Minimum payments are held constant — some lenders recalculate minimums monthly.
- Does not model balance transfers, consolidation loans, or 0% introductory offers.
- Assumes all payments are made on time every month.
Frequently asked questions
What is the avalanche method?
What is the snowball method?
Does extra payment amount matter a lot?
Should I pay off debt or invest?
Disclaimer: KalkWise calculators are provided for general informational and educational purposes only and do not constitute financial, investment, tax, or legal advice. Results are estimates based on the figures you enter and the assumptions described above. Actual outcomes will vary. Consult a qualified professional before making financial decisions.