How words and sentences are counted
A word is any run of letters or numbers separated by whitespace, so hyphenated terms like well-known and contractions like don't each count as one word, matching how most word processors behave. Sentences are detected by terminal punctuation (full stop, question mark, exclamation mark and their equivalents in other scripts) followed by a space or the end of the text. Paragraphs are blocks of text separated by one or more empty lines, or line breaks where no blank lines are used.
Character counts include every letter, number, space and symbol. The no-spaces count removes spaces, tabs and line breaks, which is what many publishers and translation agencies use for pricing.
About reading and speaking time
Adults reading non-fiction silently average roughly 238 words per minute, and a comfortable presentation pace is about 130 to 150 words per minute. Estimates are rounded to the nearest second and assume plain prose; technical writing, tables and code take longer. Treat them as planning guides rather than precise timings.