# Book Calculators

> Source: https://www.infinitelibrary.ai/calculators

Last updated: 2026-09-06

Free calculators for writers — Words to Pages, Reading Time, Audiobook Length, Writing Time, Novel Length — each answered in one line, with the reference table behind the number. Every page listed here is also available as markdown: append `.md` to its URL, or request it with `Accept: text/markdown`.

## Calculators

- [Words to Pages Calculator](https://www.infinitelibrary.ai/calculators/words-to-pages) — Words → printed pages. 50,000 words is about 150–200 pages in a printed book. At the most common trade-paperback size, 6 × 9 inches in 11-point type, it runs 152–167 pages; a 5.5 × 8.5 paperback runs 167–182, a 5 × 8 runs 179–200, and a double-spaced manuscript about 200. Enter your own word count below.
- [Reading Time Calculator](https://www.infinitelibrary.ai/calculators/reading-time) — Words → hours and minutes. At the average adult silent-reading speed of about 238 words per minute, 50,000 words takes about 3 hours 30 minutes to read, 80,000 words about 5 hours 36 minutes, and 100,000 words about 7 hours. A slow reader at 150 words per minute needs roughly half again as long; a fast reader at 300 finishes about a fifth sooner.
- [Audiobook Length Calculator](https://www.infinitelibrary.ai/calculators/audiobook-length) — Words → finished hours. A 50,000-word book makes about 5 hours 23 minutes of finished audio at the standard narration pace of 155 words per minute — the ACX rule of 9,300 words per finished hour. An 80,000-word novel runs about 8 hours 36 minutes, and 100,000 words about 10 hours 45 minutes. Slow narration adds about a fifth; brisk narration trims it.
- [How Long Does It Take to Write 50,000 Words?](https://www.infinitelibrary.ai/calculators/writing-time) — Target → writing days and a finish date. Writing 50,000 words takes 30 days at the NaNoWriMo pace of 1,667 words a day, 50 days at 1,000 words a day, and 100 days at 500. Writing five days a week instead of seven stretches those to about six, ten and twenty weeks. Enter your own target and pace below to get a finish date.
- [How Long Is a Novel? Word Counts by Category and Genre](https://www.infinitelibrary.ai/calculators/novel-length) — Word count → category, genre fit, chapters. By the SFWA's Nebula Award definitions, a short story is under 7,500 words, a novelette 7,500–17,499, a novella 17,500–39,999, and a novel 40,000 words or more. Commercially, most adult novels run 70,000–100,000 words, novellas 20,000–40,000, and a 50,000-word book is a short novel. Enter a word count to see where yours lands.

## Related

- [Writing guides](https://www.infinitelibrary.ai/guides)
- [Book publishing glossary](https://www.infinitelibrary.ai/glossary)
- [Book tools](https://www.infinitelibrary.ai/tools)
- [Book formats](https://www.infinitelibrary.ai/formats)
- [Bindery — the Claude-powered book studio](https://www.infinitelibrary.ai/bindery)

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More from Infinite Library, as one map for AI agents: https://www.infinitelibrary.ai/llms.txt