Time is length divided by speed
Reading time is estimated as ‘text length ÷ amount read per minute’. The catch is that speed is measured in different units for different languages. For space-separated languages like English it is usually words per minute (wpm), for Korean syllables (characters) per minute, and for Japanese and Chinese characters per minute.
English and other space-separated languages
In a meta-analysis of 190 studies, Brysbaert (2019) found that the average silent reading speed of adult English readers is 238 words per minute for non-fiction and 260 for fiction. The average speed for reading aloud was 183 words per minute. This tool uses 238 words for silent reading as the default. Speaking (presenting) is slower than reading aloud because of more pauses and emphasis, so the default is 150 words per minute, a commonly used presentation pace.
Korean
There are few large-scale studies of adult silent reading speed in Korean measured in characters. This tool uses 500 characters per minute as the silent reading default. In a Korean study where adults read easy sentences on screen, they read about 200 eojeol (space-separated word units) per minute — 500–600 syllables per minute for sentences averaging about 3 syllables per eojeol — and real texts are harder than that, so the value is set a little conservatively.
Speaking follows presentation and broadcasting conventions. News reading is often described as roughly 250–290 characters per minute, and calmly reading a prepared script in a presentation as about 280 characters per minute, so the default is 280 characters per minute. By this calculation, a 3-minute talk calls for a script of roughly 840 characters without spaces.
Japanese and Chinese
In IReST (Trauzettel-Klosinski et al., 2012), an international reading speed test in which the same text was read aloud in 17 languages, Japanese was read at about 357 characters per minute and Chinese at about 255 characters per minute. This tool uses these values as the speaking defaults and estimates silent reading by applying English's silent-to-aloud ratio (about 1.3×): 450 characters per minute for Japanese and 330 for Chinese. A text is treated as Japanese if it contains even one kana character, and as Chinese if it contains only Chinese characters.
Texts that mix languages
Hangul, Chinese characters/kana, and other words are counted separately, each divided by its own speed, and the results are added up. For example, if a Korean sentence contains English words, the Hangul syllables are calculated at 500 characters per minute and the English words at 238 words per minute.
The defaults are only a starting point
Reading speed varies widely between people and between texts of different difficulty. Even in the same study, individual differences exceed 20% of the average. In the tool's ‘Reading speed’ option you can choose slow (0.8×) or fast (1.25×). For a presentation script, the most accurate approach is to read it aloud once while timing yourself and adjust the speed based on the result.
Sources: Brysbaert, M. (2019). How many words do we read per minute? Journal of Memory and Language. / Trauzettel-Klosinski, S. & Dietz, K. (2012). Standardized assessment of reading performance: The New International Reading Speed Texts IReST. IOVS. / Korean study measuring Korean reading speed (Journal of the Korean Ophthalmological Society, 2016).
Last updated: 2026-09-23