GPT-4o API cost calculator
GPT-4o (OpenAI) is priced at $2.50 per million input tokens, $1.25 for cached input, and $10 per million output tokens — half that through the Batch API. Verified 2026-09-17 against OpenAI's pricing page.
What GPT-4o costs for common workloads
| Workload | Per request | Per day | Per month |
|---|---|---|---|
| Support chatbotShort turns with a reused system prompt — 3k in, 400 out, 60% cached. | $0.0092 | $46.25 | $1,388 |
| RAG over documentsRetrieved context dominates — 12k in, 500 out, 30% cached. | $0.030 | $45.75 | $1,373 |
| Coding agentGrowing context every turn — 20k in, 1.5k out, 80% cached. | $0.045 | $135 | $4,050 |
| Batch classificationTiny prompts at volume through the Batch API — 800 in, 20 out. | $0.0011 | $220 | $6,600 |
Its blast radius when an agent loops
The coding-agent workload above at 30 requests a minute — $81.00 an hour — priced at each point a team usually finds out:
Hourly alert
$81.00
Next morning
$1,944
After a weekend
$4,860
Monthly invoice
$58,320