GPT-5 mini API cost calculator
GPT-5 mini (OpenAI) is priced at $0.25 per million input tokens, $0.025 for cached input, and $2 per million output tokens — half that through the Batch API. Verified 2026-09-17 against OpenAI's pricing page.
What GPT-5 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. | $0.0011 | $5.72 | $172 |
| RAG over documentsRetrieved context dominates — 12k in, 500 out, 30% cached. | $0.0032 | $4.78 | $144 |
| Coding agentGrowing context every turn — 20k in, 1.5k out, 80% cached. | $0.0044 | $13.20 | $396 |
| Batch classificationTiny prompts at volume through the Batch API — 800 in, 20 out. | $0.0001 | $24.00 | $720 |
Its blast radius when an agent loops
The coding-agent workload above at 30 requests a minute — $7.92 an hour — priced at each point a team usually finds out:
Hourly alert
$7.92
Next morning
$190
After a weekend
$475
Monthly invoice
$5,702