Published by Sonya
See when you'll be debt-free and build a monthly payoff plan.
Sonya built this tool to help her younger brother, who had just come out of debt, keep going with checkpoints he could measure: remaining balance, estimated payoff month, and the next extra payment. It is educational planning, not financial advice.
Calculations stay in your browser · Educational only · Not financial advice
The calculator estimates a payoff month, total interest, monthly schedule, and snowball-versus-avalanche comparison. It covers minimums first, then assigns extra money by strategy.
Balances, APRs, and schedules are calculated in the browser. Do not enter account numbers or identity documents. Real accounts may use daily interest or fees outside this model.
Read the full method, tests, and limitationsThe calculator is an educational planning model. It compares strategies with the numbers you enter, keeps the work 100% browser-local, and does not create an account, upload your debt data, or store your plan on a server.
Read the privacy and terms pages for the calculator boundary: Privacy · Terms
Educational only. Not financial advice.
Enter debts, APRs, and extra monthly budget to compare Snowball, Avalanche, and custom order in real time.
| Debt Name | Balance | Min Payment | APR (%) | |
|---|---|---|---|---|
Pay highest-APR debt first. Usually saves the most interest overall.
Type the stable amount you can add every month after all minimum payments.
Simulate adding a lump-sum payment in a chosen month and see the effect on payoff time and interest.
Snowball pays off smallest balances first to create quick psychological wins. Avalanche pays highest-interest debts first and usually saves the most interest mathematically.
Model: interest accrues monthly, then minimum payments and extra budget are applied. Results are educational approximations.
Both strategies use the same monthly budget. Snowball pays the smallest balance first. Avalanche pays the highest APR first.
| Scenario | Debt details | Note |
|---|---|---|
| Mixed debt example | Credit card $4,200 at 24.9%, card $1,200 at 21.9%, student loan $9,800 at 5.5%, auto loan $7,200 at 7.9% | With $490 of minimums plus $150 extra, avalanche saves an estimated $49.10 in this reproducible example. |
| Credit-card-heavy example | Card A $3,500 at 22.9%, card B $1,800 at 19.9%, personal loan $6,500 at 12.5% | Avalanche gains more value when high-rate balances dominate. |
Compare both strategies with your own numbers · Open the full comparison guide
Educational only. Not financial advice.
Debt snowball is often easier to stick with because it pays the smallest balance first and creates quick wins. Debt avalanche usually saves more interest because it pays the highest APR first. The better plan is the one you can follow consistently.
No. Calculations, exports, and share links are handled in your browser. Balances, APRs, minimum payments, and schedules are not sent to a server.
Enter the amount you can reliably pay after covering all minimum payments. Start with a sustainable number so the plan does not compete with essential expenses.
No. Results are educational planning estimates. Real loans may have daily interest, fees, promotional rates, or prepayment rules.
The calculator uses APR divided by 12 once per simulated month. Many card issuers use daily or average-daily balances, different billing-cycle lengths, fees, grace periods, and payment-allocation rules.
The calculator shows a warning because the balance may grow before extra money is assigned. If the plan cannot reduce balances within the model limit, it returns a not-payable result instead of inventing a payoff date.
Not automatically. The model keeps the minimum you entered constant until that debt is paid. Update the input when a new statement changes the required amount.
A lump sum is applied in its selected month after required payments and follows the chosen strategy. If it pays off one target, the unused amount continues to the next eligible debt.
It does not change APR automatically on a future date. Run separate before-and-after scenarios or update the APR when the promotion ends, and use the card agreement as the source of truth.
It means the entered payments and assumptions did not produce a safe payoff schedule within 1,200 months, or the numbers exceeded the model's safe range. It is a warning to review inputs and real options, not a legal conclusion.
Every minimum is still paid first. Extra money then follows the debt order you selected, and any debts missing from an imported legacy order are appended safely.
No. Exact-plan links encode the balances and settings needed to restore the scenario. Keep them private. Public social buttons share only the canonical calculator URL, not the encoded plan.
For more answers, visit the full FAQ.