Toy Technical Debt Cost Calculator

This Calculator is a toy to show a basic cost of tech debt over time.


Initial Time Saved (P): Days saved by taking the shortcut.

Base Interest Rate (r₀): Monthly interest rate (%)

Current Commits per Month (V): # repo commits per month.

Baseline Commits per Month (V₀): avg # repo commits per month.

Time (t): # months to calculate the cost over.



Example: Say you have two options. Shortcut: takes 1 day, Right Way takes 1 week. If you save 4 days by taking a shortcut, have a 10% interest rate, and a repo with say 200 commits per month (baseline 100), the cost/amount to payback after 6 months would 12 days (basic compound interest formula). This helps you assess whether the shortcut was worth it.

Cost Growth Over Time