The detail
Paragraphs vary, but writing guides typically treat 100–200 words as a normal paragraph. At about 1.33 tokens per word, a 100-word paragraph is roughly 133 tokens and a denser 200-word paragraph is about 265 tokens.
For prompt engineering this is a handy unit: a system prompt of a few paragraphs is usually 400–800 tokens, which is small relative to modern context windows but is billed on every single request, so it adds up at volume.
Markdown formatting (headings, bullet lists, bold markers) and inline code raise the count, because each symbol and list marker tends to be its own token. Count the real formatted text for an accurate figure.