About this tool
Every LLM prices in tokens, not words. This calculator gives you a fast, model-aware estimate of how many tokens a prompt uses and what that costs across the major providers — useful before you fire off a batch job, tune a system prompt, or size a monthly budget.
How it works
- Paste the prompt (or a representative sample) into the input.
- The tool applies a heuristic token count roughly matching cl100k-base tokenization for English text.
- It then multiplies by current per-1K pricing for GPT-4o, GPT-4o-mini, Claude 3.5 Sonnet/Haiku, and Gemini 1.5.
- You get a per-request cost and a projected cost at your chosen monthly volume.
When to use it
- Sizing the cost of an automated content pipeline before you turn it on.
- Comparing whether a longer system prompt on a cheap model beats a shorter prompt on a premium one.
- Estimating a customer's monthly spend for an internal AI feature.