How to Calculate the Cost of Technical Debt

Use the Sync Tax approach. For any feature, compare the time it would take in a clean system (vacuum effort) against the time it actually takes in your current system.

If a feature should take 20 hours but takes 60 because three other modules need updates and two teams need to coordinate, that extra 40 hours is technical debt cost. Multiply by your blended hourly rate to get the dollar figure.

At $120/hour blended rate, that one feature cost $4,800 in pure debt servicing. Now multiply by every feature your team ships. The number is never small. Track this monthly and you'll see exactly when debt outweighs feature value.