Count words in a document or paragraph.
Word counting requires a tokenisation rule, and different tools apply different ones, which is why counts disagree between applications. This counter treats a run of letters, digits, apostrophes and hyphens as one word, so well-established and don't each count once — the same convention most word processors use. Standalone numbers are optional because academic word limits sometimes exclude numeric data. Average paragraph length is reported alongside because it is the more actionable figure for prose quality: paragraphs above about 150 words are visually forbidding and tend to be skimmed rather than read.
Tokenisation
A word is a run of letters, digits, apostrophes or hyphens; numbers optional
Paragraph average
Words per paragraph = total words / paragraph count
Because they tokenise differently. Some split hyphenated compounds into two words, some count standalone numerals and some do not, and treatment of footnotes, captions and citations varies. For an enforced limit, always use the count from the tool your marker or editor will use.
Sixty to 120 words for most prose. Above about 150 a paragraph looks like a block and readers skim it, which defeats the purpose of whatever is inside. If a paragraph exceeds that, it usually contains two ideas and splitting it improves both.