The customary lengths

Flash and short fiction sit under 7,500 words. Novellas run roughly 20,000 to 50,000. A standard novel is 70,000 to 100,000. Fantasy, science fiction and historical fiction commonly run 100,000 to 150,000. Epics exceed that, and are judged more harshly for it.

These are conventions, not laws — but they are the conventions readers, reviewers and storefronts have been trained by.

What length costs you

Length is the single number that governs production here. An audio book is 7.000000000000001% of word count; a film book is 12%. So 80,000 words is $5,600 in audio and $9,600 as a film book, while 140,000 words is $9,800 and $16,800.

Runtime follows the same honesty: roughly one finished minute per 1,000 words. A 90,000-word novel is about an hour and a half of finished work.

Asked and answered

How many pages is 80,000 words?

Around 300 print pages at typical trade paperback settings, though trim size, font and leading move that considerably.

Is my book too long?

If it is above 150,000 words and not epic fantasy, the length itself will be read as a lack of discipline. Cut before you cast.