About This Calculator
The AI Model Cost Calculator fetches live pricing data from OpenRouter, an API aggregator that provides access to 100+ large language models (LLMs) from providers including OpenAI, Anthropic, Google DeepMind, Meta, Mistral, Cohere and others. Select any model, enter your expected token usage, and instantly see the cost breakdown.
How AI API Pricing Works
AI language model APIs charge separately for two types of tokens:
- Input tokens — the text you send to the model (your prompt, context, chat history, documents). These are cheaper because the model processes them in one pass.
- Output tokens — the text the model generates in response. These are more expensive because generation is computed token by token.
Prices are quoted per 1 million (1M) tokens. To estimate your cost: multiply your token count by the per-token price. This calculator does that automatically for any model on OpenRouter.
What Is a Token?
A token is roughly 4 characters or ¾ of a word in English. As a rough guide:
- A short sentence (~10 words) ≈ 13–15 tokens
- A paragraph (~100 words) ≈ 130–150 tokens
- A full page of text (~500 words) ≈ 650–750 tokens
- A 10-page document (~5,000 words) ≈ 6,500–7,500 tokens
Frequently Asked Questions
How is AI model cost calculated? Total cost = (Input Tokens × input price per token) + (Output Tokens × output price per token). Providers quote prices per 1 million tokens. For example, if input costs $2.50/1M and you send 1,000 tokens, the input cost is $0.0025.
What is a token in AI models? A token is a unit of text — roughly 4 characters or ¾ of a word in English. A typical 100-word paragraph is approximately 130–150 tokens. Non-English languages often use more tokens per word.
Why are input and output tokens priced differently? Input tokens are cheaper because the model reads them in a single forward pass. Output tokens require sequential autoregressive generation — each token is computed one at a time — which is significantly more compute-intensive.
Where does the pricing data come from? Pricing is fetched live from the OpenRouter API, which aggregates 100+ models. Data is cached in your browser for 24 hours. OpenRouter's prices may differ slightly from direct provider pricing.
How many tokens does a typical ChatGPT conversation use? A short query and response might use 200–400 tokens total. A detailed technical exchange with a long reply can use 2,000–5,000 tokens or more depending on context window usage.
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