Is this book worth your time?
How the Worth-it score works
Every book on Qualisma gets two numbers: how long it takes you to read, and a Worth-it score out of 10 — whether readers think it repays those hours. Here is the whole of how the score is made.
The score in one picture
Two parts, added together: what readers think of the book, and what it costs you in hours.
A long book works the same way, with the length part taken away instead: The Brothers Karamazov scores readers 8.5 − length 0.8 = 7.7. Loved books still score highly, whatever their length.
1 · What readers think
We start from the average rating on Hardcover, a community where readers track and rate what they read — always shown as theirs, never as ours.
An average is only as good as the number of people behind it. A 5-star average from twelve readers proves little; 4.5 stars from eight thousand proves a lot. So, the way IMDb ranks films, a book with few ratings is pulled toward the average of every book we track (3.99★) until enough people have rated it to speak for itself. Then the stars become the readers' part of the score: 2.5★ is 0 and 4.7★ is 10.
2 · What it costs you in hours
Then the length. A book under 6 hours at an average pace earns a bonus of up to +0.5; a longer one costs up to −1.0. Every doubling of length moves the score by the same small step, and the caps mean length can tip a close call but never outvote the readers.
See the numbers
| Reading time | Effect on the score |
|---|---|
| 1 hr | +0.5 |
| 2 hrs | +0.5 |
| 3 hrs | +0.4 |
| 4 hrs | +0.2 |
| 6 hrs | no change |
| 8 hrs | −0.2 |
| 12 hrs | −0.4 |
| 16 hrs | −0.6 |
| 24 hrs | −0.8 |
| 32 hrs | −1.0 |
| 48 hrs | −1.0 |
3 · The verdict
The two parts add up to a score out of 10, and every score comes with plain words:
- 8.0 – 10Well worth the time
- 6.5 – 7.9Worth the time
- 5.0 – 6.4Worth it for some readers
- 0.0 – 4.9A hard sell for the time
A book with 10–49 ratings gets an early score, drawn in a lighter ring, that will move as more readers rate it. Under 10 ratings there is no score yet — the reading time is still there.
And the reading time
The hours come from the page count, checked across Open Library, Hardcover and Google Books, at about 300 words a page. At an average 250 words a minute a 300-page book is about 6 hrs.
For classics in the public domain we don't estimate at all: we count every word of the complete text from Project Gutenberg. Page counts are least reliable exactly there — editions of War and Peace run from about 700 pages to well over 1,300 — while the text is the text. Those books say “counted word for word” on their page. Set your own reading speed — or take the 30-second test — and every time on the site adjusts to you. The score does not: it judges length at the average pace, so it is the same for everyone.
Common questions
- What does the Worth-it score mean?
- It answers one question: is this book worth the hours it takes? It starts from how readers rate the book — Hardcover's community average, adjusted for how many people have rated it — then adds a small bonus for a short book or a small cost for a long one. 8 or more: well worth the time. 6.5 to 7.9: worth the time. 5 to 6.4: worth it for some readers. Below 5: a hard sell for the time.
- Why do short books get a bonus?
- Because the question is about your time. When two books are loved equally, the one that asks for three hours is an easier yes than the one that asks for thirty. The bonus is small — at most 0.5 of a point — so a short book still has to be well liked to score well.
- Does a long book always score low?
- No. Length takes away at most 1.0 point, so a book readers love still scores highly: The Brothers Karamazov takes about 23½ hrs at an average pace and scores 7.7.
- Where do the ratings come from?
- From Hardcover, a community where readers track and rate what they read. We always show their average as theirs, next to the score, and never present it as a rating of our own. When few people have rated a book, its average is pulled toward the average of every book we track (3.99 out of 5), so a dozen enthusiastic readers cannot put a book at the top.
- Why does a book have no score yet?
- We score a book once at least 10 people have rated it. Between 10 and 49 ratings the score is marked early and drawn in a lighter ring: it leans on the library average and will move as more people rate the book. Brand-new releases often start with no score.
- Does my reading speed change the score?
- No. Length is judged at an average pace of 250 words a minute, so the score is the same for everyone, and the same when you share it. Your reading speed changes the hours we show you, not the score.
- Can a score be bought or set by hand?
- No. Every score comes from the same two inputs and the same arithmetic, recalculated every week when the ratings and page counts are refreshed. Some links to booksellers earn us a commission; they have no effect on any score.