Debt payoff calculator
Compare the snowball and avalanche methods across all your debts and see your debt-free date.
About the debt payoff calculator
Compare the snowball and avalanche methods across all your debts and see your debt-free date.
Part of SmartCalcy’s finance tools. It runs in your browser with no account, uses your own currency and units (change them at the top of the page), and gives estimates for information only, so check official guidance before you rely on a result.
How to use the debt payoff calculator
What it calculates and when to use it
Compares the snowball and avalanche methods across several debts, showing your debt-free date, interest paid and the order in which debts are cleared.
How to use it, step by step
- List each debt with its balance, interest rate and minimum payment.
- Enter the extra money you can pay each month.
- Choose avalanche (highest rate first) or snowball (smallest balance first).
- Compare the results.
What each input means
- Balance, Rate %, Minimum – For each debt.
- Extra – Added to the minimums and aimed at the target debt.
- Method – Decides which debt receives the extra money.
How to read the results
- Debt-free in – Months until all balances are zero.
- Interest – Total interest for each method and for minimum payments only.
- Order – When each debt is cleared.
The formula
Each month interest = balance × rate ÷ 12 is added, minimums are paid, and the remaining budget goes to the target debt. When a debt is cleared its minimum rolls into the next one.
A worked example
A credit card of 4,500 at 22.9%, a car loan of 9,000 at 7.5% and a store card of 1,200 at 29.9%, with 200 extra a month. You are debt-free in 2 years 4 months and pay 2,115 interest, compared with 3 years 11 months and 4,712 at the minimums, a saving of 2,596.
Assumptions and limits
- Rates are fixed and no new debt is added.
- Minimums do not change as balances fall.
Common mistakes
- Not rolling a cleared debt’s payment into the next one.
- Paying only minimums on high-rate cards.
Frequently asked questions
Avalanche or snowball?
Avalanche costs less interest. Snowball gives quicker wins. Pick the one you will stick to.
Why does it say my debt never clears?
A minimum payment smaller than the monthly interest means the balance never falls.
Related tools
Details
- Total paid
- £16,815
- Avalanche
- 2 years, 4 months, £2,115 interest
- Snowball
- 2 years, 4 months, £2,115 interest
- Minimum payments only
- 3 years, 11 months, £4,712 interest
- Interest saved by your extra payment
- £2,596
- Total monthly payment
- £620.00
Order the debts are cleared
| Debt | Paid off after |
|---|---|
| Store card | 6 months |
| Credit card | 1 year, 6 months |
| Car loan | 2 years, 4 months |