The formula uses words and an assumed speed
Divide the word count by words per minute to obtain minutes. At 240 words per minute, 1,440 words give six minutes. At 180, the same material gives eight. The calculator does not observe your reading, attention or comprehension. Change the assumption to match the person and the kind of text rather than treating the default as a universal average.
Silent reading and speaking are different tasks
A spoken script needs room for breath, emphasis, audience reactions and transitions. A silent-reading estimate cannot be copied directly into a speech schedule. The editor offers separate reading and speaking speeds so you can compare them without changing the text. Use the spoken track for the words someone will actually say, not every word projected on a slide.
Worked example
1,440 words
| 180 words/min | 8 minutes |
|---|---|
| 240 words/min | 6 minutes |
| 300 words/min | 4 min 48 sec |
Reserve non-speaking time before drafting
A ten-minute slot with three minutes for a demonstration has seven minutes available for voice. At an illustrative 130 words per minute, that gives 910 words as a first budget. Do not add overlapping visual footage to the duration a second time. Separate consecutive silent segments from pictures shown while narration continues.
Choose the scope of the material
A title, reference list, stage direction or subtitle may be visible without being spoken. Measure the spoken passage separately and keep a short inventory of other segments. A presentation’s notes and slide text should not be added automatically. If the goal is an article reading label, state which article parts that label includes.
Validate with a timed sample
Record a representative section at the intended pace. Include difficult names, explanations and demonstrations, then compare the observed duration with the estimate. Revise meaningfully instead of speeding up every sentence to meet a number. The downloaded report records the selected rate; it is not proof that every reader will finish in that time.