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302.AI LLM Token Calculator

Instantly estimate API costs for GPT, Claude, Gemini, and 100+ AI models. Plan your AI budget with precision — free, no sign-up required.

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💬 Output (Response)

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Learn

Understanding LLM Tokens & Costs

Everything you need to know to budget your AI API usage effectively.

What Is a Token?

A token is the smallest unit of text that an LLM processes. In English, 1 token ≈ 4 characters or about ¾ of a word. "Hello world!" is roughly 3 tokens. Tokens are not the same as words — punctuation and spaces also consume tokens.

Chinese vs. English Tokens

Chinese characters are denser. Each Chinese character typically uses 1–2 tokens, while 1 English word averages ~1.3 tokens. This means Chinese text is often more token-efficient per semantic unit than English.

Input vs. Output Cost

Most providers charge input and output tokens separately. Output tokens typically cost 2–4× more than input tokens because generation is computationally heavier than reading. Always account for both when budgeting.

Context Window

The context window is the total number of tokens (input + output) a model can handle in a single request. Larger windows (e.g. 128K, 1M) allow longer documents but also cost more per call if fully utilized.

How Is LLM API Cost Calculated?

LLM API cost = (Input Tokens × input price + Output Tokens × output price) ÷ 1,000,000. Input and output tokens are priced separately, and output tokens typically cost 2–4× more since text generation is computationally heavier.

Choosing the Right Model

Not every task needs the SOTA models. For classification, summarization, or simple Q&A, smaller models cost 10–50× less with comparable quality. Match model capability to task complexity.

📊 Word-to-Token Conversion Guide

Estimated token counts vary by content type. Use this guide to better predict your token usage.

Content Type	Token Ratio	1,000 Words Estimate	Notes
🇺🇸 English Text	~1.3 tokens/word	≈ 1,300–1,500	Standard prose, articles, emails
💻 Code (Python/JS)	~2–3 tokens/word	≈ 2,000–3,000	Keywords, operators, symbols add tokens
🀄 Chinese / Japanese	~2+ tokens/char	≈ 2,000+	Each CJK character uses 1–2 tokens
📝 Technical Writing	~1.5 tokens/word	≈ 1,500–1,800	Jargon, acronyms, numbers increase count
🗃️ JSON / XML Data	~3–4 tokens/word	≈ 3,000–4,000	Brackets, quotes, keys all consume tokens

FAQ

Frequently Asked Questions

Common questions about LLM API tokens and cost calculation.

What is a token in LLM APIs?

A token is the fundamental unit of text that language models process. In English, 1 token is approximately 4 characters or ¾ of a word. For example, "ChatGPT is great!" contains roughly 6 tokens. Chinese characters are typically 1–2 tokens each. Most LLM providers charge based on the total number of input and output tokens processed per API call.

How is LLM API cost calculated?

LLM API cost follows this formula:

Total Cost = (Input Tokens ÷ 1,000,000 × Input Price) + (Output Tokens ÷ 1,000,000 × Output Price)

Input tokens are your prompt (instructions + context), while output tokens are the generated response. Output tokens are usually priced 2–4× higher than input tokens. The 302.AI Token Calculator computes this automatically for each selected model.

Which AI models does this calculator support?

The 302.AI Token Calculator supports 100+ models including:

OpenAI: GPT-4o, GPT-4o mini, GPT-4 Turbo, o1, o3
Anthropic: Claude 3.5 Sonnet, Claude 3 Opus, Claude 3 Haiku
Google: Gemini 1.5 Pro, Gemini 1.5 Flash, Gemini 2.0
Meta: LLaMA 3.1 (8B, 70B, 405B)
Mistral AI: Mistral Large, Mistral Medium, Codestral
And many more via the 302.AI unified API

What currencies does the calculator support?

The calculator supports four currencies:

USD — US Dollar (default)
CNY — Chinese Yuan (人民币)
JPY — Japanese Yen (日本円)
RUB — Russian Ruble (Российский рубль)

Exchange rates are updated periodically. For real-time billing, final amounts are determined by 302.AI's current exchange rate at the time of API call.

What is the difference between input and output tokens?

Input tokens are everything you send to the model: your system prompt, conversation history, user message, and any injected context (RAG documents, etc.).

Output tokens are the tokens the model generates in its response. Since text generation is computationally more expensive than processing input, output tokens typically cost 2–4× more per token.

For chatbots with long conversation histories, input tokens can accumulate rapidly as the full context is resent with each turn.

How does 302.AI pricing compare to direct API pricing?

302.AI provides access to 100+ models through a single unified API, with pricing that mirrors or improves upon the direct provider rates. Additional benefits include:

Pay-as-you-go with no monthly minimums
No separate accounts for each model provider
Consistent API format across all models (OpenAI-compatible)
Access to models not directly available in your region
Usage dashboard and cost tracking built-in

Is the calculator free? Do I need a 302.AI account?

The Token Calculator is completely free to use, with no account required. It's a planning tool to help developers and teams estimate API costs before building.

When you're ready to start using the APIs, you can sign up for 302.AI for free and get started with pay-as-you-go access to all supported models.

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