A reading-time estimate can help plan a script or study session. It cannot tell you exactly when a sentence occurred in a recording unless the source timing is already known.
Calculate the planning estimate
Divide the word count by words per minute to get an approximate duration in minutes. Adjust the pace to your audience and purpose. Reading silently, explaining a concept and delivering a script are different activities.
Measure your own pace
Use a representative text and the words-per-minute timer. Start when you begin reading and stop when you finish. A comprehension check matters: a very fast pass is not the same as understanding the material.
Create chapter drafts from paragraphs
The timestamp generator assigns estimated durations from paragraph word counts and a chosen speaking pace. It is useful for a script outline or rough chapter plan. It does not listen to audio or detect actual scene boundaries.
Replace estimates before publishing
Listen to the recording and update the chapter starts. Pauses, demonstrations and music change elapsed time without adding words. Keep the label estimated until every published marker has been checked against the source.