o3-mini API cost calculator
o3-mini (OpenAI) is priced at $1.10 per million input tokens, $0.55 for cached input, and $4.40 per million output tokens — half that through the Batch API. Verified 2026-09-17 against OpenAI's pricing page.
What o3-mini 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. | $0.0041 | $20.35 | $611 |
| RAG over documentsRetrieved context dominates — 12k in, 500 out, 30% cached. | $0.013 | $20.13 | $604 |
| Coding agentGrowing context every turn — 20k in, 1.5k out, 80% cached. | $0.020 | $59.40 | $1,782 |
| Batch classificationTiny prompts at volume through the Batch API — 800 in, 20 out. | $0.0005 | $96.80 | $2,904 |
Its blast radius when an agent loops
The coding-agent workload above at 30 requests a minute — $35.64 an hour — priced at each point a team usually finds out:
Hourly alert
$35.64
Next morning
$855
After a weekend
$2,138
Monthly invoice
$25,661