How long is a story? Obviously it is as long as it needs to be . . . to be told. However there are expectations. Firstly, there is a semi-rigid classification into:
Flash Fiction – up to 300 words (Bridport Prize up to 250)
Short Story – 250/300 up to 7,500 words (Bridport 5,000; Bristol 4,000)
Novelette (a term conjured from the blue) – 7,500 to 17,500 words
Novella – 17,500 to 40,000
Novel – 40,000 +
But it’s not as simple as that: the expected wordcount varies with genre . . .
Crime/detective novels average around 70-80,000
Sci-Fi/Fantasy around 90-120,000
And with the age of the reader . . .
Young adult fiction 55-70,000
Children no more than 40,000
So, how do already published novels reflect these wordcount recommendations:
Pride and Prejudice – 120,697 words
Lord of the Rings (3 volumes) – 455,125 words
Atonement – 123,378 words
HP and the Philosopher’s Stone – 77,325 words
HP and the Deathly Hallows – 198,227 words
But these were Halcyon days, writers . . . because now it has become a matter of economics . . . ink and paper cost money. So first time authors are being warned to keep their stories below 100,000 words AND that means that I am currently reducing the novel I have just completed from 123,000 words . . . but oh, what a waste of carefully crafted sentences, of nuances of plot and character detail . . .
Jean E Levy 
What i do not realize is if truth be told how you’re not really much more neatly-preferred than you may be now.
You’re so intelligent. You recognize therefore significantly relating to this matter, made me
individually consider it from a lot of various angles.
Its like men and women don’t seem to be fascinated except it is one thing to accomplish with
Lady gaga! Your personal stuffs nice. Always care for it up!