o3-pro API cost calculator
o3-pro (OpenAI) is priced at $20 per million input tokens, $20 for cached input, and $80 per million output tokens — half that through the Batch API. Verified 2026-09-17 against OpenAI's pricing page.
What o3-pro 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. | $0.092 | $460 | $13,800 |
| RAG over documentsRetrieved context dominates — 12k in, 500 out, 30% cached. | $0.280 | $420 | $12,600 |
| Coding agentGrowing context every turn — 20k in, 1.5k out, 80% cached. | $0.520 | $1,560 | $46,800 |
| Batch classificationTiny prompts at volume through the Batch API — 800 in, 20 out. | $0.0088 | $1,760 | $52,800 |
Its blast radius when an agent loops
The coding-agent workload above at 30 requests a minute — $936 an hour — priced at each point a team usually finds out:
Hourly alert
$936
Next morning
$22,464
After a weekend
$56,160
Monthly invoice
$673,920