AI Coding Assistant Productivity ROI Calculator
Calculate the return on AI coding assistants (GitHub Copilot, Cursor, Codeium, Tabnine, JetBrains AI) — developer hours times measured productivity gain times fully loaded engineering cost minus license spend. Get a per-developer monthly net benefit and team-wide annual savings.
What the Research Actually Shows
The 2024 GitHub-Microsoft randomized controlled trial of 4867 developers found Copilot users completed tasks 26 percent faster on average, with newer developers (under 5 years) seeing 27-39 percent gains and senior developers seeing 8-13 percent. METR's 2025 independent study put real-world gain at 10-18 percent (lower than vendor claims). McKinsey's 2024 study aligned with the higher range for greenfield code (35-55 percent faster) but found near-zero gain for legacy code maintenance. Pick your assumption carefully.
ROI Formula
Monthly Savings = Devs × Hours/Month × Productivity Gain % × Loaded Hourly Cost
Net ROI = (Savings - License Spend) / License Spend × 100
License Pricing as of 2026
GitHub Copilot Business: USD 19/dev/month, Copilot Enterprise: USD 39/dev/month. Cursor Pro: USD 20/dev/month, Cursor Business: USD 40/dev/month. Codeium Teams: USD 12/dev/month. JetBrains AI Pro: USD 20/dev/month. Amazon Q Developer Pro: USD 19/dev/month. Self-hosted options (Continue, Tabby) trade license fees for inference cost — budget USD 30-80/dev/month in LLM bills.
Why Most ROI Cases Are Wrong
Common errors: (1) using vendor-quoted productivity numbers (always optimistic), (2) measuring only code-writing time when the dev cycle includes debugging, reviewing, testing, and meetings, (3) ignoring code review burden — AI-generated code needs more review, not less. The realistic adjustment: multiply your raw productivity gain by the share of dev time spent actually coding (typically 25-40 percent, not 100 percent). A 30 percent coding-time productivity gain on a dev who codes 30 percent of the week is a 9 percent net hour gain.
How to Build a Defensible Business Case
Use coding-time-only productivity gains from peer-reviewed research (15-25 percent is the safe band), apply the coding-time share of total dev time, and use fully loaded engineering cost (salary times 1.4 for benefits and overhead, divided by 1900 working hours). Subtract license cost. Year-one ROI of 200-400 percent is realistic; vendor claims of 1000 percent plus are usually wrong. Track actual productivity through cycle time and PR throughput, not LOC.
Sources: GitHub-Microsoft RCT 2024 (Cui et al.), METR Productivity Study 2025, McKinsey GenAI in Software Engineering 2024, GitHub Pricing (2026), Cursor Pricing (2026). Last updated: April 2026.