Method & assumptions
How DebtPathway works
No black box. Here is exactly how the calculator turns your balances into a payoff date and an interest total.
The monthly loop
For every month, in order, the calculator:
- Adds interest. Each debt's balance grows by its monthly rate — your APR divided by 12. A 24% APR adds 2% to that balance that month.
- Pays the minimums. Every debt gets at least its minimum payment (or its remaining balance, if that's smaller).
- Attacks one target. Whatever money is left — your extra payment plus any minimums freed up by debts already paid off — goes entirely to the current target debt. Avalanche targets the highest APR; snowball targets the smallest balance — see the full snowball vs. avalanche comparison.
- Rolls over. When a debt hits zero, the total you pay each month doesn't drop — it shifts to the next debt. This is what makes the plan speed up over time.
It repeats until every balance is zero, counting the months and adding up the interest along the way. Amounts are rounded to the cent each month, the way a real statement works.
Assumptions
- Your APR is fixed for the life of the payoff.
- You pay the same total every month and never miss a payment. (The total is your minimums plus your extra.)
- Minimum payments are treated as fixed dollar amounts, not a shrinking percentage of the balance. Real card minimums often fall as the balance drops, which would slightly slow a minimum-only payoff — so a minimum-only plan in real life can be even slower than shown.
- No new charges are added to any debt.
- Fees, promotional rates, and taxes aren't modeled.
When a plan “never pays off”
If your total monthly payment is smaller than the interest piling on across all your debts, the balance can only grow — there's no payoff date to show. When that happens, the calculator tells you instead of inventing a number. Adding to your monthly payment, or lowering a rate, fixes it.
Your privacy
Everything above happens in your browser. Your balances and rates are never sent to a server, never stored, and never shared. Close the tab and they're gone.