There is no single reading speed, so the tool gives you a range rather than a false precision:
- 225 words per minute is the common average for silent reading of general prose. Technical or unfamiliar material is slower.
- 150 words per minute is a careful read — the pace of somebody reading a contract, or of a proofreader.
- 130 words per minute is a calm speaking pace. A five-minute talk is roughly 650 words.