OPENAI / GPT · UPDATED JUL 2026

OpenAI API Pricing Calculator — GPT-4o, GPT-5, GPT-5.6

Estimate your monthly OpenAI API bill from real usage numbers, across GPT-4o, GPT-5, and the GPT-5.6 family (Luna / Terra / Sol).

OpenAI pricing at a glance

ModelInput $/1MOutput $/1MBest for
GPT-4o$2.50$10.00Established multimodal flagship
GPT-5$1.25$10.00Reasoning, 400K context
GPT-5.6 Luna$1.00$6.00High-volume, low-cost tasks
GPT-5.6 Terra$2.50$15.00Balanced mid-tier tasks
GPT-5.6 Sol$5.00$30.00Hardest reasoning tasks

See OpenAI's official pricing page →

Frequently asked questions

How much does the OpenAI API cost?

GPT-4o is $2.50/$10.00 per million input/output tokens, GPT-5 is about $1.25/$10.00, and the GPT-5.6 family spans $1.00/$6.00 (Luna) to $5.00/$30.00 (Sol). Rates change — verify on OpenAI's pricing page.

Is GPT-5 cheaper than GPT-4o?

GPT-5 is usually cheaper on input tokens despite stronger reasoning and a bigger context window. Your exact savings depend on your input/output ratio — use the calculator above with your real numbers.

Does OpenAI offer batch discounts?

Yes, the Batch API typically cuts prices by around 50% for asynchronous (non-instant) jobs. Toggle "Batch mode" in the calculator to see the effect.

Compare against Claude and Gemini

Want the full picture across providers? Use the universal LLM cost calculator to compare OpenAI against Anthropic's Claude models and Google's Gemini models side by side for the same workload.