Prompt Token Counter
Count the exact number of tokens used by a prompt before sending it to an LLM.
Inputs
Estimated Tokens
21
Characters
84
Words
14
Step by step
Character count
len(text)
= 84
Token estimate: chars ÷ chars/token
84 ÷ 4
= 21
How it works
Token counting estimates how many tokens a prompt will consume. Most modern LLMs use BPE tokenization where ~4 characters equals one token for English text. Knowing exact token usage helps stay within context limits and predict costs.
Formula
Token Estimate
tokens ≈ character_count / chars_per_token
- chars_per_token
- Average characters per token (≈4 for English BPE)
Frequently Asked Questions
Why is this an estimate?
Exact token counts depend on the specific tokenizer (GPT uses tiktoken, Claude uses its own). The 4-char rule is a reliable heuristic for English but varies by language.
How do special characters affect token count?
Special characters, code, and non-English text often tokenize less efficiently (more tokens per character), so the actual count may be higher than the estimate.