OpenAI token calculator — GPT-5.6, GPT-4.1 & GPT-4o

It counts the tokens in the text you paste, estimates how many tokens a typical reply will use based on the output size you pick, and multiplies both by each provider's published per-token rate to show an approximate API cost.

A token is a chunk of text a language model reads at a time — often a word, part of a word, or a punctuation mark. English text averages roughly four characters per token, so a 1,000-word document is usually somewhere around 1,300–1,500 tokens.

OpenAI counts are computed with the same tokenizer OpenAI's models use, so they're exact. Other providers don't publish a tokenizer that runs in a browser, so those figures are close estimates based on character density — usually within a few percent of the real count.

Generating new text takes more computation than reading existing text, so most providers price output tokens several times higher than input tokens — often 3 to 6 times as much on flagship models.

Rates are entered manually from provider documentation and reviewed periodically. Providers change pricing without much notice, so confirm against the provider's own pricing page before budgeting a production workload.

You can paste anything. Code and non-English text often tokenize less predictably than English prose, so treat the estimate as directional rather than exact for those cases.