GPT-4o mini API cost calculator
GPT-4o mini (OpenAI) is priced at $0.15 per million input tokens, $0.075 for cached input, and $0.6 per million output tokens — half that through the Batch API. Verified 2026-09-17 against OpenAI's pricing page.
What GPT-4o 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. | $0.0006 | $2.77 | $83.25 |
| RAG over documentsRetrieved context dominates — 12k in, 500 out, 30% cached. | $0.0018 | $2.74 | $82.35 |
| Coding agentGrowing context every turn — 20k in, 1.5k out, 80% cached. | $0.0027 | $8.10 | $243 |
| Batch classificationTiny prompts at volume through the Batch API — 800 in, 20 out. | $0.0001 | $13.20 | $396 |
Its blast radius when an agent loops
The coding-agent workload above at 30 requests a minute — $4.86 an hour — priced at each point a team usually finds out:
Hourly alert
$4.86
Next morning
$117
After a weekend
$292
Monthly invoice
$3,499