Free AI Token Counter & Cost Calculator

How to Use the AI Token Counter & Cost Calculator

Count tokens, estimate AI API cost, check context-window usage, and compare supported models in a few seconds. The calculator is designed to answer the questions that matter before you send a prompt: How many tokens will this use, will it fit, and what could it cost?

1. Paste or type your prompt into the text box above.
2. Select a model such as GPT-5.6, Claude Sonnet 5, or Gemini.
3. Review the result for estimated tokens, API cost, context usage, and the lowest-cost supported option.
4. Open the comparison or budget planner only when you need to compare models or estimate monthly usage.

Everything runs in your browser. There is no sign-up required, and the text you paste into the tool is not sent to CountFlows for token counting or cost calculation.

What Is an AI Token Counter?

An AI token counter estimates how many tokens a language model may use to process your text. Tokens are the units models work with internally: a token can be a whole word, part of a word, punctuation, or another small text unit. Tokenization varies by model and language, so a word count and a token count are not interchangeable.

For English text, a useful rule of thumb is that one token is roughly four characters or about three-quarters of a word. That means 1,000 English words are often around 1,300 tokens, not 1,000 tokens. Code, JSON, unusual vocabulary, and non-Latin languages can produce very different ratios.

A basic token counter stops at the number. CountFlows goes further by combining an AI token calculator with cost estimation, context-window checking, model comparison, and a lightweight monthly budget planner so you can make a decision rather than just read a count.

How Token Counting and AI API Cost Estimation Work

AI providers generally charge separately for input tokens and output tokens. Your pasted prompt contributes to the input side; the model's reply contributes to the output side. If you select an expected response length, the calculator adds that estimate to show a more realistic round-trip cost.

The core calculation is straightforward:

The total shown by this token cost calculator is an estimate based on the pricing data configured for each model. Actual API billing can differ because providers may apply cached-input pricing, long-context tiers, batch discounts, tools, search calls, image or audio charges, or other model-specific billing rules.

GPT, Claude & Gemini Token Cost Comparison

The table below is a compact reference for several models supported by the tool. Prices are in USD per 1 million text tokens and reflect official provider pricing checked on August 15, 2026. AI pricing changes frequently, so production budgets should always be verified against the provider before deployment.

* Gemini 3.1 Pro uses higher rates for prompts above 200K tokens. ** Gemini 3.6 Flash is currently on promotional pricing through December 31, 2026. OpenAI also applies higher long-context rates to GPT-5.6 requests above its long-context pricing threshold. These special tiers should be reflected in the calculator's model-pricing data.

GPT Token Counter

Use the model selector as a GPT token counter to estimate prompt size and API cost for supported GPT models. GPT-5.6 Sol, Terra, and Luna share a large context window but have very different input and output prices, so the cheapest choice can change significantly at scale.

Claude Token Counter

A Claude token counter is useful when budgeting long documents, coding sessions, RAG context, or agent workflows. Claude Sonnet 5 and Opus-class models support large context windows, but their tokenizer behavior and pricing differ from GPT models, so treat cross-provider counts as estimates rather than identical measurements.

Gemini Token Counter

Use the same text as a Gemini token counter to compare Gemini's cost and context capacity with GPT and Claude. Gemini pricing can include model-specific tiers and promotional rates, which is why the tool focuses on an estimated decision view instead of pretending every provider bills the same way.

Context Window Checker: Will Your Prompt Fit?

A model's context window is the maximum amount of tokenized information it can work with in a request or conversation, subject to the provider's model rules. The context checker compares your estimated input plus the selected response allowance with that limit and shows how much room remains.

This matters for long PDFs, research notes, codebases, chat history, RAG pipelines, and large system prompts. If your content is close to the limit, shorten the prompt, retrieve only the most relevant context, split the job into smaller requests, or choose a model with a larger context window.

Token Budget Planner: Estimate Monthly AI API Spend

A single API request can cost fractions of a cent, which makes it easy to underestimate the monthly bill. The budget planner turns a model's per-token rate into a practical workload estimate. Enter your expected monthly budget plus average input and output tokens per request to see approximately how many requests that budget can support.

This makes the page useful as a lightweight LLM cost calculator for early planning. It is especially helpful for high-volume chatbots, content workflows, support automation, and developer tools where a small difference in cost per request can become significant across thousands of calls.

How Many Tokens Are in 1,000 Words?

There is no fixed words-to-tokens conversion, but the following English-language estimates are useful for quick planning. Actual tokenization depends on the model, vocabulary, punctuation, formatting, code, and language.

If you only need document length, use the Word Counter. If you need AI-processing size, context fit, and estimated API cost, use the token calculator above.

Who Should Use This AI Token Calculator?

Developers & AI Engineers

Estimate prompt size before an API call, compare model costs, check context limits, and get a quick sense of monthly usage before moving a workload into production.

Prompt Engineers & Agent Builders

Test whether large system prompts, tool instructions, retrieved context, or multi-step agent inputs are becoming unnecessarily expensive. A smaller prompt can reduce cost and preserve more context for the model's output.

Writers, Researchers & SEO Teams

Check long articles, research notes, briefs, and documents before sending them to an AI model for summarization, analysis, or rewriting. For cleanup after generation, use the AI Text Cleaner.

Founders & Teams Planning AI Spend

Compare the economics of different models before committing to a provider. The cost comparison and budget planner are useful for rough planning, while final procurement decisions should use your provider's current official pricing and your own production usage data.

Accuracy & Pricing Transparency

Tokenization is model-specific. The CountFlows calculator currently provides an estimated token count; it should not be described as an exact provider-side billing count unless the tool is using that provider's official or model-matched tokenizer. The final usage reported by an API provider is the authoritative number for billing.

Cost estimates are only as current as the pricing data behind them. CountFlows reviews model pricing manually, but providers can change rates, context limits, cached-token discounts, and model availability. For that reason, this page shows a verification date and avoids presenting estimates as guaranteed invoices.

Private Browser-Based Token Counting

The AI Token Counter performs its text analysis and arithmetic in your browser. Your pasted prompt is not uploaded to CountFlows for these calculations. That makes the tool practical for drafts, code, prompts, and other text you do not want to send to an additional server just to estimate token usage.

More Free Text & SEO Tools

• Word Counter — count words and characters as you type.
• Character Counter — check text length against platform limits.
• AI Text Cleaner — remove markdown, hidden characters, and unwanted AI formatting.
• Keyword Density Checker — review keyword usage before publishing.
• Case Converter — switch text between sentence case, title case, uppercase, and more.