AI API Cost Calculator

Claude API pricing varies by model tier. Claude Fable 5.2, released November 9, 2026 and the top generally available tier, costs $8/1M input tokens and $40/1M output tokens, 20 percent under Claude Fable 5.1 at $10/$50, with cache reads at $0.20. Claude Opus 5.5, released September 22, 2026 and still Anthropic's recommended starting point for most workloads, is $4/1M input and $20/1M output with cache reads at $0.20. Claude Opus 5 remains available at $5/1M input and $25/1M output, and Claude Sonnet 5.5 is $2/1M input and $10/1M output; all of these ship with a 1M context window. Claude Haiku 5.5, released October 7, 2026, is the most affordable at $0.10/1M input and $0.50/1M output for prompts up to 100K tokens (longer prompts bill $0.50/$2.50 on every token), also with a 1M context window. The previous budget model, Claude Haiku 4.5, is $1/1M input and $5/1M output with a 200K context window.

In our pricing data, the cheapest paid APIs include NVIDIA Nemotron 3.5 Lightning at $0.08/1M input tokens, and poolside Laguna S 2.1, OpenAI GPT-6 Luna, and Anthropic Claude Haiku 5.5 (prompts up to 100K tokens) at $0.10/1M input. Google shut down Gemini 2.0 Flash, once a $0.10 budget default, on June 1, 2026. Open-weight models like DeepSeek V4.1 Flash and Qwen3.8-27B are free to self-host, though you will pay for compute infrastructure.

AI tokens are the basic units of text that language models process. One token is roughly 4 characters or about 0.75 words in English. A 1,000-word article is approximately 1,333 tokens. Pricing is typically quoted per 1 million tokens, with input (prompt) and output (completion) priced separately.

The best AI API for production depends on your use case. Claude Sonnet 5.5 and GPT-6 Sol offer strong all-around performance at the same $2/$10 rate, and Sonnet 5.5 ranked second on the Vals Index on its October 18, 2026 board update. For budget-sensitive applications, GPT-6 Luna, Claude Haiku 5.5, and Gemini 3.8 Flash deliver solid results at a fraction of the price. For tasks requiring deep reasoning, Claude Fable 5.2 leads the Vals Index at $8/$40 (71.31 percent, November 9, 2026), Claude Opus 5.5 sits third on the independent Artificial Analysis Intelligence Index (59, November 9) at $4/$20, Gemini 4 Argon is a strong option (budget it at $4/$20 from December 1), and GPT-6 Astra and Claude Fable 5.1 sit at $10/$50.