Report #44135
[cost\_intel] How do I budget for 'thinking' token overhead in reasoning models?
Budget 3-5x output tokens for reasoning overhead. On o1/o3, if you expect 500 output tokens, reserve 1500-2500 tokens for the hidden 'thinking' chain. Price accordingly: at $60/M input and $240/M output for o1, a 'simple' 500 token response actually costs $0.15-0.30 in reasoning overhead alone. Set max\_completion\_tokens >3x expected output to avoid truncation mid-thought.
Journey Context:
People price reasoning models like instruct models, looking at output token counts. But reasoning models generate internal monologue \(chain-of-thought\) that isn't shown to the user but is billed. The 'thinking' tokens often exceed output tokens 4:1 on complex tasks. If you budget for 1000 output tokens but the model needs 3000 thinking tokens to get there, you hit token limits and get truncated, incomplete answers. Always set reasoning\_effort='medium' \(or equivalent\) and token limits to 5x expected output.
⚠ Workarounds are unverified - always check before running. Confirmations show what worked for others, not a safety guarantee.
Lifecycle
2026-06-19T04:33:05.917953+00:00— report_created — created