o1 · OpenAI
First-generation deep reasoning flagship for complex mathematics and STEM problems.
Last checked Aug 19, 2026. Calculations use the listed base rates; provider-specific tiers, cache writes, batch pricing, and long-context rules may differ. Confirm the current rate at the official provider source.
Input
$15.00
per 1M tokens
Output
$60.00
per 1M tokens
Cached input
$7.50
per 1M tokens
Context window
200K
max output 100K
o1 (Reasoning) cost calculator
What o1 (Reasoning) costs per task
| Use case | Input tokens | Output tokens | Cost / request | Monthly @ 1K req/day |
|---|---|---|---|---|
| Customer support chatbot | 3,500 | 350 | $0.0551 | $1,653.75 |
| RAG / search-augmented answers | 8,000 | 500 | $0.12 | $3,600.00 |
| AI coding assistant | 12,000 | 2,000 | $0.246 | $7,380.00 |
| Document summarization | 25,000 | 600 | $0.3922 | $11,767.50 |
| Agentic workflow | 40,000 | 1,500 | $0.495 | $14,850.00 |
| Content generation | 800 | 1,200 | $0.0822 | $2,466.00 |
| Data extraction & tagging | 2,000 | 250 | $0.042 | $1,260.00 |
| Translation | 5,000 | 5,500 | $0.3994 | $11,981.25 |
Assumes each use case's typical cacheable share of input. See full cost scenarios.
Compare with alternatives
| Model | Input /M | Output /M | Context | Chat request* |
|---|---|---|---|---|
| o1 (Reasoning) | $15.00 | $60.00 | 200K | $0.093 |
| GPT-5.6 Sol | $5.00 | $30.00 | 1.1M | $0.035 |
| GPT-5.6 Terra | $2.00 | $12.00 | 1.1M | $0.014 |
| GPT-5.6 Luna | $0.20 | $1.20 | 1.1M | $0.0014 |
| GPT-5.6 Cyber | $12.50 | $75.00 | 1.1M | $0.0875 |
| GPT-5.5 Standard | $5.00 | $30.00 | 512K | $0.035 |
| GPT-5.5 Pro | $30.00 | $180.00 | 512K | $0.21 |
| GPT-5.4 Workhorse | $2.50 | $15.00 | 256K | $0.0175 |
| GPT-5.4 mini | $0.75 | $4.50 | 256K | $0.00525 |
*4,000 in + 800 out tokens, 50% cached input where available.
Related calculations
FAQ
o1 (Reasoning) costs $15.00 per 1M input tokens and $60.00 per 1M output tokens, with cached input at $7.50 per 1M tokens. Verified Aug 19, 2026 against https://openai.com/api/pricing.
o1 (Reasoning) supports a 200,000-token context window with up to 100,000 output tokens per request, tokenized with o200k_base.
At $15.00/M input and $60.00/M output, o1 (Reasoning) sits above GPT-5.6 Sol ($5.00/M in, $30.00/M out) — see the comparison table for full-workload differences.