How sentences are detected
A sentence ends at a period, question mark, or exclamation point followed by a space, or at a line break. Abbreviations such as “e.g.” can occasionally be counted as a sentence end, so treat the count as a close estimate.
Reading and speaking time
Reading time assumes 238 words per minute, the average silent reading speed measured for adults reading non-fiction in English. Speaking time assumes 130 words per minute, a comfortable pace for a presentation.
Sentence length
Average sentence length is a quick readability check. Plain-language guides commonly suggest averaging 20 words or fewer per sentence for web and business writing.