Word count, reading time and the limits people enforce
Two writers hand in "800 words" and one of them is a third longer than the other. Both are telling the truth. Word count is not one measurement — it depends on what you count as a word, what you count as text, and whether the thing enforcing the limit is counting words at all.
Reading time is one division
The "5 min read" on an article is not a measurement of anything. It is word count divided by a reading speed, and the near-universal figure is 200 words per minute. The word counter uses exactly that, then rounds:
199 words shows as < 1 min. 200 words is 1 min. 500 words rounds to 3 min — not two and a half, because half rounds up. 1,000 words is 5 min, 1,500 is 8 min.
200 wpm is a reasonable average for adult silent reading of ordinary prose. It is badly wrong for anything else: dense technical writing runs slower, and a page of code or numbers is not read left to right at all. Treat the badge as a rough promise about length, which is what readers use it for.
Words, characters and the gap between them
A word, for counting purposes, is a run of characters separated by whitespace. That means "state-of-the-art" is one word and "state of the art" is four, an em dash surrounded by spaces counts as a word on some tools, and a URL is one word however long it is. There is no standard, only conventions.
Characters are less ambiguous but come in two flavours — with and without spaces — and the difference is roughly 18% of your text. Always check which one a limit means, because the platforms that count characters almost always count them with spaces.
Which limit is really being applied
Most of the limits writers hit are character limits wearing a word-count costume:
A search result snippet is truncated by pixel width, not characters — the ~155-character guidance is a proxy, and a line of capitals gets cut earlier. A UCAS personal statement is 4,000 characters and 47 lines, whichever runs out first, and blank lines count. Social bios and headlines are characters. Academic abstracts are words. Essay limits are words but marked with a tolerance nobody publishes.
The practical rule: find out whether the limit is words, characters-with-spaces or lines before you write to it, and write to about 95% of it. Editing 200 words out of a finished piece is much harder than leaving room.
Sentences and paragraphs are the useful counts
The count that actually improves writing is not the total. It is the ratio: words divided by sentences. Push much past 25 and prose starts to feel like wading, whatever the total length. Watching sentence count climb alongside word count as you draft is the cheapest self-edit there is — and it is why the counter reports sentences and paragraphs rather than just the headline figure.
The other habit worth having: check the count in the tool that will enforce it, not the one you drafted in. Word processors, form fields and CMS editors disagree, and the one that matters is the last one.