Speech Time Calculator — Words to Minutes

Spoken length is governed by one ratio: your speaking rate, measured in words per minute (wpm). The estimate is deliberately simple and fully deterministic — no hidden fudge factors, so you can reproduce every number by hand.

1. Count the words. Pasted text is trimmed and split on any run of whitespace, dropping empty tokens: text.trim().split(/\s+/).filter(Boolean).length. Or you type a word count directly.
2. Pick a rate R. The default is 150 wpm — the conversational English average reported by the National Center for Voice and Speech. Toastmasters recommends 125–150 wpm for clear delivery, which frames the slow (110) and fast (170) presets.
3. Compute spoken time. T = words × (60 ÷ R) seconds. For example 1,500 words at 150 wpm = 1500 × (60 ÷ 150) = 600 seconds = 10 min 0 sec.
4. Format. The exact seconds are rounded to the nearest whole second, which naturally carries 60 s into the next minute and 60 min into an hour. Past one hour the result is shown as H:MM:SS.
5. Reverse mode. Given a target of S seconds, the words to script are W = round(R × (S ÷ 60)). A 5-minute (300 s) talk at 150 wpm needs 150 × 5 = 750 words.
6. Silent reading comparison. The same word count is also timed at 238wpm — the mean silent reading rate for English non-fiction from Brysbaert's 2019 meta-analysis. Reading in your head is about 60% faster than speaking, which is why a script that feels short on paper over-runs when delivered.

The same answer is computed two ways internally — the seconds-per-word form words × (60 ÷ R) and the division-first form (words ÷ R) × 60 — and they must agree. As a third sanity check, the 150 wpm default implies 9,000 finished words per hour, which sits inside the audiobook industry's ACX standard of roughly 9,000–9,600 words per finished hour.

• National Center for Voice and Speech (NCVS), University of Utah — conversational rate ≈ 150 wpm
• Toastmasters International, “Your Speaking Voice” (Item 199) — 125–150 wpm for clear public speaking
• ACX / Audible audiobook narration standard — 150–160 wpm (≈ 9,000–9,600 words per finished hour)
• Brysbaert, M. (2019), Journal of Memory and Language vol. 109 — mean silent reading rate ≈ 238 wpm

Speaking and reading rates on this page were last cross-checked against the four sources above on Jun 22, 2026. Found a pace that's off for your use case? Email me and I'll review it.