Paid script
Debt Payoff Planner (Python script)
List your debts, add what extra you can pay each month, and see exactly how long each strategy takes and what it costs in interest.
Paid script
Debt Payoff Planner Python script
Buy this script on its own for $19, one time. No membership needed. It runs on your own computer and nothing you enter leaves it. Read how it works and the questions below first.
The Personal Finance Suite includes this and 3 more tools for $29. Members get this included. See the membership or sign in. Already bought it? Email me my access link.
How it works
How it works
Each month the script adds interest, pays every minimum, and rolls your extra money plus the minimums freed by paid-off debts onto the target debt. Avalanche targets the highest rate first, which minimizes total interest. Snowball targets the smallest balance first, which gives quick wins. It compares both with paying only minimums, flags any debt whose minimum does not cover its interest, and can write the full month-by-month schedule to a CSV. Pure Python, no installs, nothing leaves your computer.
FAQ
About this calculator
Which is better, avalanche or snowball?
Avalanche costs less interest. Snowball can be easier to stick with because the first debts disappear sooner. The script shows the dollar and time difference for your own debts so you can decide.
What does it assume?
Fixed rates, no new charges and on-time payments. Variable rates, promotional rates that expire and new borrowing will change the real result.
Is this financial advice?
No. It is a planning calculator for general information.
Is anything saved?
No. The math runs in your browser and nothing you enter is sent to us.
Is this tax or financial advice?
No. It is a calculator for general information. Check the numbers against your own records, and ask an accountant before you act on them.
Related: simple interest calculator, compound interest calculator. See all free tools. More free tools: NPV calculator, Rule of 72 calculator, Weighted average calculator, or see all free tools.
Free
Month-End Close Checklist (PDF)
The five-day close, one page to print. Enter your email and we send a link to confirm it is yours, then the download. We may email you about new toolkits, and every email has an unsubscribe link.
General information, not tax or legal advice. How we write and check our tools.