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ReadLength
Doyle, Arthur Conan · d. 1930 · measured edition

The Sign of the Four

2h 53mof reading at 250 wpm

The Sign of the Four by Doyle, Arthur Conan runs to 43,211 words — about 2h 53m of reading at an average adult pace of 250 words per minute, or roughly 157 pages at typical paperback density.

Extent 43,211 words · 5,543 distinct forms · 2,451 sentences · F–K grade 6.8

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

Extent — 157 pages against 2h 53m 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

Words43,211longer than 16% of books here
Reading time2h 53mat 250 wpm
Reading level6.8Flesch–Kincaid grade
Chapters123,601 words each

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: 43,211 words, 2,451 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
43,211 ÷ 250 wpm   = 173 min   → 2h 53m
words ÷ density         = extent
43,211 ÷ 275 w/pp  = 157 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) 4h 48m10 days5 days
Below average (200 wpm) 3h 36m8 days4 days
Average adult (250 wpm) 2h 53m6 days3 days
Fast (300 wpm) 2h 24m5 days3 days
Very fast (450 wpm) 1h 36m4 days2 days

The full measurement

Total words43,211
Unique words5,543
Lexical diversity12.83% unique words as a share of total
Sentences2,451
Average sentence length17.6 words
Average syllables per word1.32
Long words (3+ syllables)6.7%
Chapters detected12 — averaging 3,601 words
Flesch–Kincaid grade6.8
Flesch reading ease77.5 higher is easier; 60–70 is plain English
Gunning fog index9.7
Coleman–Liau index6.9

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. 2097·REVIEWED JUL 2026

Reading it in evenings

The same 43,211 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 18 days
20 min a day 9 days
30 min a day 6 days
60 min a day 3 days
Worked from the text: 43,211 words ÷ 250 words per minute = 173 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 straightforward — middle school level: Flesch–Kincaid puts it at grade 6.8, Gunning fog at 9.7, Coleman–Liau at 6.9. The Flesch reading-ease score of 77.5 sits in genuinely plain-English territory.

The mechanics behind that: sentences average 17.6 words (modern prose tends to run 15–20), and 6.7% of words are three syllables or longer. Its vocabulary is unusually varied — 5,543 distinct words, or 12.83% 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 Sign of the Four?

43,211 words in the Project Gutenberg edition, made up of 5,543 distinct words across 2,451 sentences. That is longer than 16% of the books measured on this site.

How long does it take to read The Sign of the Four?

About 2h 53m at an average adult reading speed of 250 words per minute. A slower reader at 150 wpm would need roughly 4h 48m; a fast reader at 400 wpm about 1h 48m.

What reading level is The Sign of the Four?

It scores 6.8 on the Flesch–Kincaid grade scale — straightforward — middle school level. Its Flesch reading-ease score is 77.5, sentences average 17.6 words, and 6.7% of its words run to three syllables or more.

How many pages is The Sign of the Four?

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, 43,211 words works out to roughly 157 pages.

Colophon

Measured from the Project Gutenberg plain-text edition, ebook no. 2097, with Gutenberg’s header and licence footer struck before counting. 43,211 words, 2,451 sentences, 5,543 distinct forms. No text of the work is set anywhere on this site — only measurements of it.

The extent of 157 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. 2097·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.

See all 10 sites in this family, with what each one answers

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