Ask HN: How many hours (on average) does it take you to finish a technical book?

Depends on the book.

Many of them I don't finish. Some because starting the book meant just sort of browsing around and they stayed that way. Some that I started and read sequentially until I didn't and then maybe I browse in it or maybe I don't. Some because the book's content gets beyond my knowledge or interests or both.

Of the technical books I finish, it depends on the book. Depth of content, my level of relevant knowledge and the length of the book all play a role.

The pace at which I tend to read technical books when I am committed to reading them (but perhaps not finishing them) tends to be about twenty or so pages a night most nights while I am in that mode. That might mean ten pages a night for a deeply technical book (or thirty if it is so deep I am skimming it). It rarely involves doing exercises though sometimes it involves reading them.

For full clarity, I don't really worry about what I miss or not getting 'everything' out of everything I read. A lot of books are over my head. A lot extend beyond my interests. Also, I'm not in a hurry because the more other things I learn, the more I will tend to get out of any particular book.

Measure your reading rate in pages/hour over a year. I average 33 pages per hour. My wife reads faster than I do, although the only measure is that she completes the same books faster (she has never tried measuring). As for understanding, I average 3 books on any given subject, 5 on some. The first book is really just an introduction to the subject (regardless of whether that is the target audience). The second book is much clearer because the terms are clear and the "goal" of formulas make sense. By the third book I can usually manipulate the ideas well. These days I usually also watch several youtube videos related to the subject. When using the material I often revisit certain books. I have several books that have chapters falling out from overuse, so "finishing a book" is not a way to think about it, more like "paging out to backing store" so I can retrieve it when I need it.

3-4 hours a chapter, just like in college. Math books more, books in a domain I'm familiar with less.

I'm always going back to them, never 'finished'