GPT Token Pricing: How to Calculate True AI Costs
What is a token? Learn how OpenAI, Anthropic, and Google calculate token pricing and how to accurately predict your API bills.
When you look at the pricing page for OpenAI or Anthropic, you won't see prices listed "per word" or "per character." Instead, every major AI provider bills based on Tokens.
If you want to accurately predict your API costs, you must understand how token pricing works.
What is a Token?
A token is the fundamental unit of data processed by a Large Language Model (LLM).
Tokens do not map cleanly to whole words. Instead, they represent common sequences of characters. For example, a short, common word like "apple" might be a single token, while a complex word like "unprecedented" might be broken into two or three separate tokens ("un", "preced", "ented").
The Golden Rule of Tokens:
- 1 Token ≈ 4 characters in English.
- 100 Tokens ≈ 75 English words.
This means if you want an AI to generate a 750-word blog post, you will be billed for approximately 1,000 output tokens.
Input vs. Output Tokens
AI providers charge different rates depending on whether they are reading text or generating text.
- Input Tokens (Prompt Tokens): This is the text you send to the API. Input tokens are cheap to process because the model reads them all at once in parallel.
- Output Tokens (Completion Tokens): This is the text the AI generates and sends back to you. Output tokens are significantly more expensive (often 3x to 5x higher) because the model must generate them sequentially, one by one, requiring much more compute power.
For example, OpenAI's GPT-5.5 charges $5 per 1M input tokens, but the price jumps to $30 per 1M output tokens.
Multilingual Token Penalties
The 100 tokens = 75 words rule primarily applies to English.
Because modern tokenizers were trained heavily on English datasets, they are highly optimized for English vocabulary. If you send prompts in Japanese, Hindi, or Arabic, the tokenizer cannot group letters as efficiently.
As a result, a 75-word sentence in Korean might consume 200 to 300 tokens instead of 100. If you are building a multi-lingual app, your token costs will inherently be higher.
Automate Your Token Math
You don't need to do the math manually. We built a calculator that takes your expected word counts, automatically applies tokenizer conversions, and outputs your exact monthly cost across all major providers.