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ReadLength
Boyle, Robert · d. 1691 · measured edition

The Sceptical Chymist

5h 54mof reading at 250 wpm

The Sceptical Chymist by Boyle, Robert runs to 88,499 words — about 5h 54m of reading at an average adult pace of 250 words per minute, or roughly 322 pages at typical paperback density.

Extent 88,499 words · 6,899 distinct forms · 1,586 sentences · F–K grade 23.8

SOURCE·Project Gutenberg full texts·computed from the full text·REVIEWED JUL 2026

Extent — 322 pages against 5h 54m of reading

Above the rule one mark per reading hour at 250 wpmBelow a folio every 50 pages at 275 words to the page

SOURCE·Project Gutenberg full texts·counted from the text, not a publisher's page count·REVIEWED JUL 2026

Words88,499longer than 46% of books here
Reading time5h 54mat 250 wpm
Reading level23.8Flesch–Kincaid grade
Unique words6,899vocabulary size

How this is worked out

  1. The Project Gutenberg plain-text edition is fetched, then Gutenberg's header and licence footer are struck at the *** START *** and *** END *** markers. Nothing is taken from a publisher's listing.
  2. What remains is counted as that edition sets it: 88,499 words, 1,586 sentences, syllables by vowel-group heuristic.
  3. Words are divided by a stated reading rate. This page's headline uses 250 words a minute; a duration printed without its rate cannot be checked, so the rate travels with every figure and the table below runs 150–450 wpm.
  4. Minutes are rounded once, to the nearest minute, and set as h:mm. Nothing on this page is rounded twice.
  5. The page extent is a courtesy conversion at 275 words to the page — a typesetting figure, not a property of the book.
words ÷ rate            = minutes
88,499 ÷ 250 wpm   = 354 min   → 5h 54m
words ÷ density         = extent
88,499 ÷ 275 w/pp  = 322 pages

The method in full, including why your count may differ →

How long it takes to read, by reading speed

Most adults read prose at 200–300 words per minute. Reading speed varies far more between people than most reading-time estimates admit, so here is the whole range.

Reading speedTotal timeAt 30 min/dayAt 1 hour/day
Slow / careful (150 wpm) 9h 50m20 days10 days
Below average (200 wpm) 7h 22m15 days8 days
Average adult (250 wpm) 5h 54m12 days6 days
Fast (300 wpm) 4h 55m10 days5 days
Very fast (450 wpm) 3h 17m7 days4 days

The full measurement

Total words88,499
Unique words6,899
Lexical diversity7.8% unique words as a share of total
Sentences1,586
Average sentence length55.8 words
Average syllables per word1.49
Long words (3+ syllables)12.4%
Flesch–Kincaid grade23.8
Flesch reading ease23.9 higher is easier; 60–70 is plain English
Gunning fog index27.3
Coleman–Liau index10.5

Computed from the Project Gutenberg plain-text edition with the Gutenberg header and licence footer removed. See how and why your count may differ.

SOURCE·Project Gutenberg full texts·ebook no. 22914·REVIEWED JUL 2026

Reading it in evenings

The same 88,499 words, divided by the habit rather than by the hour — and then a rate of your own, if 250 wpm is not yours.

10 min a day 36 days
20 min a day 18 days
30 min a day 12 days
60 min a day 6 days
Worked from the text: 88,499 words ÷ 250 words per minute = 354 minutes of reading, divided by the daily habit and rounded up to whole days.

SOURCE·Project Gutenberg full texts·reading rate stated: 250 wpm·REVIEWED JUL 2026

Average adult prose speed is 200–300 wpm. Not sure? Time yourself on one page.

Is it a hard read?

Four different readability formulas agree it is very difficult — postgraduate level: Flesch–Kincaid puts it at grade 23.8, Gunning fog at 27.3, Coleman–Liau at 10.5. The Flesch reading-ease score of 23.9 is heavy going by modern standards.

The mechanics behind that: sentences average 55.8 words (modern prose tends to run 15–20), and 12.4% of words are three syllables or longer. Its vocabulary is moderately varied — 6,899 distinct words, or 7.8% of the total.

A caution about all of this: readability formulas measure sentence and word length, nothing more. They cannot see irony, dialect, allusion or an unreliable narrator. A book can score as "easy" and still be genuinely difficult to follow.

The second question

What people ask once the duration is on the table.

How many words are in The Sceptical Chymist?

88,499 words in the Project Gutenberg edition, made up of 6,899 distinct words across 1,586 sentences. That is longer than 46% of the books measured on this site.

How long does it take to read The Sceptical Chymist?

About 5h 54m at an average adult reading speed of 250 words per minute. A slower reader at 150 wpm would need roughly 9h 50m; a fast reader at 400 wpm about 3h 41m.

What reading level is The Sceptical Chymist?

It scores 23.8 on the Flesch–Kincaid grade scale — very difficult — postgraduate level. Its Flesch reading-ease score is 23.9, sentences average 55.8 words, and 12.4% of its words run to three syllables or more.

How many pages is The Sceptical Chymist?

Page counts depend entirely on the edition — font, trim size and margins all change them, which is why this site measures words instead. At a typical trade-paperback density of about 275 words per page, 88,499 words works out to roughly 322 pages.

Colophon

Measured from the Project Gutenberg plain-text edition, ebook no. 22914, with Gutenberg’s header and licence footer struck before counting. 88,499 words, 1,586 sentences, 6,899 distinct forms. No text of the work is set anywhere on this site — only measurements of it.

The extent of 322 pages is a conversion at 275 words to the page, not this edition’s foliation: a page count belongs to a typesetting, never to a book. Reading time assumes 250 words a minute and is stated with its rate everywhere it appears.

SOURCE·Project Gutenberg ebook no. 22914·US public domain·REVIEWED JUL 2026

Word counts and reading levels are computed from a specific public-domain edition and will differ from other editions and from other counting methods — see the method page.

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