Tech Debt Cost Calculator
Quantify the real cost of deferred technical investment. Built for PE diligence and portfolio executive conversations.
How the calculator works
Cost model
The calculator estimates the annual carrying cost of technical debt by multiplying engineering labor cost by the maintenance burden percentage. Direct monthly cost = team size × (salary / 12) × (maintenance burden %) × velocity multiplier. When advanced mode is enabled, incident response cost (incidents × mean time to resolve × hourly rate) is added.
DORA velocity multiplier
Deployment frequency serves as a proxy for delivery friction. The multiplier (0.8×–2.4×) is applied to direct labor cost to reflect the productivity overhead associated with slower release cycles. Tiers follow the DORA State of DevOps classification: Elite (multiple/day–daily), High (weekly–biweekly), Medium (3-week–monthly), Low (quarterly–annually). Source: Forsgren, N., Humble, J., & Kim, G., Accelerate (2018); DORA State of DevOps Reports (2019–2023).
Maintenance burden benchmarks
Thresholds are calibrated for PE buy-side diligence where growth velocity is the priority. Below 10% is well-managed with capacity directed forward. 10–15% is acceptable but belongs on a 100-day remediation plan. 15–25% is a yellow flag that warrants investigation into SDLC maturity, architecture, test coverage, and deployment practices. 25–40% is a red flag signaling strategic liability: expect architectural problems, manual processes, and talent risk. Above 40% represents deal risk where the platform may require restructuring post-close. These thresholds are informed by GST’s direct experience across 100+ technology diligence engagements.
Payback analysis
The break-even period divides the remediation budget by monthly savings (equal to total monthly debt cost). This assumes full resolution of identified debt, which is a simplification. Real remediation programs typically achieve 50–80% efficiency. The estimate should be treated as a lower bound.
Limitations
This model produces order-of-magnitude estimates, not precise valuations. It does not account for context-switching overhead, team ramp-up time, partial remediation efficiency, revenue impact of incidents, or the war-room effect (larger teams pull more responders per incident, which the single-responder model understates). Salary inputs are all-in (base + benefits + equity) and should reflect loaded cost. Results are most useful for framing diligence conversations and scoping remediation budgets, not for formal valuation adjustments.
Currency
Non-USD currencies use static mid-market approximations fixed at tool release, March 2026 (EUR 0.92, GBP 0.79, CAD 1.36, AUD 1.53). For valuation work, apply current exchange rates to the USD figure.
Privacy
All calculations run entirely in your browser—no inputs are sent to our servers. Anonymous page-view and interaction analytics (Google Analytics 4) help us improve the tool. See our privacy policy for details.
Methodology last updated March 2026