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AI Vendor Lock-In Cost.

"How locked-in are we, really?" Most exec teams find out at renewal — when the leverage conversation is already over. This calculator estimates the all-in cost of leaving one AI vendor today, plus a lock-in multiplier (switching cost ÷ annual fee) that sorts vendors into four bands: portable · committed · locked · captured. Pair with the SLA Negotiator for the renewal walkthrough and the Vendor Renewal Decision for the keep/replace verdict.

Inputs

All numbers are yours. Math runs in your browser; nothing leaves.

Annual vendor spend ($) The base fee — what you'd save if you walked away tomorrow. Excludes implementation costs you already paid (those are sunk).

Data egress volume to migrate (GB) Your raw data + derived artifacts (embeddings, fine-tunes). If you can't estimate, ask the vendor's customer success team — they should know. If they don't, that's its own finding.

Egress cost per GB ($) Cloud-standard is $0.05–$0.12/GB. Some AI vendors waive egress in their contract — set to 0 if your contract confirms it. Some charge egress + per-API-call retrieval fees — that's the high end.

Retrain / rebuild hours

240 hr

Eng/ML hours to retrain a fine-tune, rebuild a RAG corpus, port prompts, recompute embeddings on the new vendor. 80–500 hr typical for one model dependency; 1000+ hr if you have multiple fine-tunes or a custom pipeline.

Retooling FTE-months

3 mo

Engineering FTE-months to re-integrate the new vendor: SDK swap, auth flow, monitoring, eval harness, runbook updates. 1–6 FTE-months typical; longer if the vendor is woven through many products.

Switching grace period — months running both vendors

2 mo

Overlap where you pay both vendors during migration. 1-2 mo for a clean cutover; 3-6 mo for a phased migration with parallel traffic. Set to 0 only if you have a hard switchover (rare and risky).

Loaded FTE cost per year ($) Salary + benefits + overhead for the engineers doing the migration. US senior IC ≈ $200–260K. Use your real loaded rate, not a market-rate guess.

Verdict

You are —

Move the sliders to see the math update.

All-in switching cost

$—

egress + retrain + retooling + parallel

Lock-in multiplier

—×

switching cost ÷ annual fee

Cost breakdown

Egress

$—

Retrain / rebuild

$—

Retooling

$—

Parallel-run

$—

The math, on the page

Four components, all transparent. Argue with the framework by running them yourself.

Component	Formula
Egress	`egressGb × egressPricePerGb`
Retrain / rebuild	`retrainHours × (fteCost / 2080)`
Retooling	`retoolingMonths × (fteCost / 12)`
Parallel-run	`graceMonths × (annualSpend / 12)`
Total switching cost	`egress + retrain + retooling + parallel`
Lock-in multiplier	`total / annualSpend`

Verdict bands: < 0.5× portable · 0.5–1.5× committed · 1.5–3.0× locked · > 3.0× captured.

What this calculator deliberately doesn't model: opportunity cost of staying (the value a better vendor would deliver), brand/customer-trust cost of switching during a public renewal, regulatory cost of a re-attestation cycle on the new vendor. Use the number as a floor on the leverage conversation, not as a final verdict.

Note on egress assumption: Many AI vendors don't expose raw data egress as a line item — you may be migrating prompts + configurations + outputs but rebuilding embeddings from scratch on the new side. If that's your case, set egress GB to 0 and put the equivalent eng-hours into the retrain bar.