A Python-based utility to plan and simulate multi-card debt repayment strategies with fixed maximum monthly payments, minimum due rules, and avalanche payoff logic.

• CSV-based input
  Upload a cards.csv with the following columns:

  • Card → Name/identifier
  • Balance → Starting balance
  • APR → Annual interest rate (decimal, e.g. 0.24 for 24%)
  • Min_Pct → (optional) Minimum payment as a % of balance
  • Min_Override → (optional) Fixed minimum payment amount

• Minima handling

  • If Min_Override is given → it takes precedence as the exact minimum.
  • If only Min_Pct is provided → minimum is computed as % of balance.
  • If both are missing → minimum due is treated as 2% of balance + interest on balance amount before payment.

• Budget guarantee

  • If your Max Allowed Payment is less than the sum of all minima, the system automatically raises the total monthly payment to at least that sum.
  • This prevents underpaying minimum dues across cards.

• Avalanche payoff

  • Extra funds beyond the minima are always applied to the highest-APR card with a balance.
  • Once that card is cleared, the next-highest APR card takes over the extra.

• Interest accrual

  • Interest compounds monthly at APR / 12.
  • Payments are applied after interest accrual each cycle.

• Multiple interfaces

  • CLI → Run in terminal.
  • Streamlit App → Simple dashboard with tables, charts, and downloads.
  • Gradio App → Interactive web UI with Plotly charts and file downloads.

• Per-card schedules (month-by-month: interest, payment, remaining balance).
• Monthly summary (how much was paid to each card and total per cycle).
• Overall summary (per card: months until payoff, total paid, total interest).
• Downloads:
  • Excel workbook (all schedules in separate sheets).
  • CSV exports (monthly allocation, summary, per-card schedules).

The flowchart below illustrates how the tool processes inputs, allocates payments, and generates outputs:

1. Clone this repo or copy the files.
2. Install dependencies:

   pip install -r requirements.txt
   
   

pandas
streamlit
gradio
plotly

python v5/amort_cli.py cards.csv --max 1000

streamlit run v5/amort_streamlit.py

python v5/amort_gradio.py

Suppose you have:

• Card A → Balance 10,000 @ 24% APR, Min_Override = 1549
• Card B → Balance 5,000 @ 18% APR, Min_Override = 1594
• Card C → Balance 2,500 @ 12% APR, Min_Override = 1638

If user input Max Allowed = 1000:

• System detects sum of overrides = 4771.
• Budget is raised to 4771, not 1000.
• Each card gets its override (1549, 1594, 1638).
• Extra budget (if any above overrides) goes toward the highest-APR card.

• Maximum simulation length: 600 months (50 years).
• Payments never exceed balance.
• Empty/malformed CSV rows are skipped safely.

The Amortization Schedule Tool is provided for informational and educational purposes only. While we strive to ensure the accuracy of the calculations, the results generated by this tool are estimates and may not reflect actual loan terms, interest rates, fees, or other financial conditions.

Users should not rely solely on this tool for making financial, investment, or legal decisions. It is strongly recommended that you consult with a qualified financial advisor, lender, or other professional before taking any action based on the information provided by this tool.

We do not accept any liability for losses or damages resulting from the use of this tool. By using this tool, you agree to use it at your own risk.

MIT — Free for personal and commercial use.

For questions, feedback, or feature requests, reach out at [email protected]