Robert Louis Stevenson · 1883
About one unknown word every twelve at a 5,000-word vocabulary. Readable, but it wants support — and that band is also where readers most easily fall into flow.
Coverage = the share of words in the text you already know. The research gives two lines: 98% before independent fluent reading is realistic, 95% for the instructional level that needs support (Hu & Nation, 2000). Proper nouns are not counted as unknown — recognising that it is a name is enough; this book has 270 of them.
Comfortable from about 8,000 words, or read it with glosses. 68,272 words in total; at 150 words a minute for a non-native reader, about 7 h 35 min to finish. Average sentence length 17.4 words. Reaching 95% coverage on this book (the floor for readability) takes roughly 12,250 word families.
The opening of Treasure Island, word for word. Tap any word you don't know and its meaning here appears beside it — no sign-up, tap as often as you like.
Squire Trelawney, Dr. Livesey, and the rest of these gentlemen having asked me to write down the whole particulars about Treasure Island, from the beginning to the end, keeping nothing back but the bearings of the island, and that only because there is still treasure not yet lifted, I take up my pen in the year of grace 17—, and go back to the time when my father kept the Admiral Benbow inn and the brown old seaman with the sabre cut first took up his lodging under our roof.
I remember him as if it were yesterday, as he came plodding to the inn door, his sea-chest following behind him in a hand-barrow--a tall, strong, heavy, nut-brown man, his tarry pigtail falling over the shoulder of his soiled blue coat, his hands ragged and scarred, with black, broken nails, and the sabre cut across one cheek, a dirty, livid white. I remember him looking round the cove and whistling to himself as he did so, and then breaking out in that old sea-song that he sang so often afterwards:
“Fifteen men on the dead man’s chest-- Yo-ho-ho, and a bottle of rum!”
in the high, old tottering voice that seemed to have been tuned and broken at the capstan bars. Then he rapped on the door with a bit of stick like a handspike that he carried, and when my father appeared, called roughly for a glass of rum. This, when it was brought to him, he drank slowly, like a connoisseur, lingering on the taste and still looking about him at the cliffs and up at our signboard.
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These are already built, and closest in difficulty to Treasure Island.
Ordered by unknown words per 100. Lower reads easier; to step up a level, pick a higher number.
Computed by Readii from the public-domain text (updated 2026-10-21), not estimated by hand. The Readii reading level is our own scale, anchored on unknown-word density; it is not the same system as Lexile or AR and does not convert directly. Unknown words are counted against a frequency list built from a large subtitle corpus, so the bands mean the same thing for any learner of English, whatever your first language. This is difficulty for a non-native reader, not a native-child reading level.