book length cheat sheet

children's books & short stories

picture books: 300-800 words

flash fiction: 300-1,500 words 

early readers: 200-3,500 words

short story: 1,500-30,000 words 

young adult: 50,000-80,000 words

fiction & novels

novellas: 30,000-50,000 words

novels: 50,000-110,000 words

romance: 70,000-100,000 words

science fiction: 90,000-120,000 words

fantasy: 90,000-120,000 words

historical fiction: 80,000-100,000 words

crime: 70,000-90,000 words

nonfiction

standard non-fiction: 70,000-80,000 words

memoir: 80,000-100,000 words

biography: 80,000-200,000 words

self-help: 40,000-50,000 words