How to Use LLM Vendor Lock-In Cost
The LLM Vendor Lock-In Cost calculator estimates engineering hours from prompt complexity and eval suite size, applies your engineer hourly rate, adds downtime opportunity cost, and computes payback if the new vendor offers a discount.
What It Does
Use the calculator with intent
The LLM Vendor Lock-In Cost calculator estimates engineering hours from prompt complexity and eval suite size, applies your engineer hourly rate, adds downtime opportunity cost, and computes payback if the new vendor offers a discount.
AI engineering leads, founders, and procurement teams sizing the cost of moving off OpenAI, Anthropic, or any other LLM provider.
Interpreting Results
Payback months under 12 is typically a green light if you also have technical reasons to switch (latency, capability, support). Higher than 24 months and you usually want to wait for vendor pricing to converge.
Input Steps
Field by field
- 1
Enter inputs
Enter your current LLM bill so downtime opportunity cost has a basis to scale against.
- 2
Rate
Rate prompt complexity 1 to 10 — the multiplier that turns into prompt-rewrite engineering hours.
- 3
Number
Number of evaluation tests that will need to be re-run or re-calibrated against the new vendor.
- 4
Loaded
Loaded engineering rate (wage + benefits + tooling). BLS data pegs senior software engineer loaded cost at $100 to $200/hr in the US.
Use a blended rate if the team mixes seniority levels.
- 5
Discount
Discount the new vendor offers vs current spend. Drives the payback months calculation.
Common Scenarios
Use realistic starting points
Small-team migration
Current monthly spend
2000
Prompt complexity
4
Eval suite size
30
Total switching cost typically 1 to 3 months of current spend.
Enterprise migration
Current monthly spend
100000
Prompt complexity
10
Eval suite size
800
Engineering hours can dominate downtime cost; check the total payback months.
Try These Tools
Run the numbers next
AI Stack Cost Calculator
Estimate your full AI app stack cost at different user scales — hosting, DB, auth, AI API, and services.
Model Price Drop Stress Test
Margin under 10/30/50% LLM price drops with both keep-savings and pass-through views.
Build vs Buy Decision Engine
Compare building infrastructure yourself versus buying managed services with per-component build/buy verdicts.
FAQ
Questions people ask next
The short answers readers usually want after the first pass.
Sources & References
- BLS — Software Developer Wages — U.S. Bureau of Labor Statistics
- Stack Overflow Developer Survey — Stack Overflow
Related Content
Keep the topic connected
What Is Gross Margin? Simply Explained
Understand Gross Margin: the vital profitability metric revealing how much revenue remains after covering direct production costs. Learn its calculation.
What Is Burn Rate? Simply Explained
Understand 'Burn Rate' – the speed a startup spends cash before generating revenue. Learn its calculation, impact on runway, and why managing.
What Is Payback Period? Simply Explained
Understand Payback Period, a critical unit-economics metric for entrepreneurs to assess investment recovery time. Learn its calculation, importance.