GPT-5.5 API cost calculator
GPT-5.5 (OpenAI) is priced at $5 per million input tokens, $0.5 for cached input, and $30 per million output tokens — half that through the Batch API. Verified 2026-09-17 against OpenAI's pricing page.
What GPT-5.5 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. | $0.019 | $94.50 | $2,835 |
| RAG over documentsRetrieved context dominates — 12k in, 500 out, 30% cached. | $0.059 | $88.20 | $2,646 |
| Coding agentGrowing context every turn — 20k in, 1.5k out, 80% cached. | $0.073 | $219 | $6,570 |
| Batch classificationTiny prompts at volume through the Batch API — 800 in, 20 out. | $0.0023 | $460 | $13,800 |
Its blast radius when an agent loops
The coding-agent workload above at 30 requests a minute — $131 an hour — priced at each point a team usually finds out:
Hourly alert
$131
Next morning
$3,154
After a weekend
$7,884
Monthly invoice
$94,608