The number of words in your writing project may not matter to you, but it very well may matter to potential agents and publishers... even readers! While quality of words definitely counts more than quantity, it couldn't hurt to get a feel for the current market averages.
The Science Fiction and Fantasy Writers of America specifies word lengths for each category of its Nebula award categories as follows:
Short story — under 7,500 words
Novelette — 7,500 to 17,500 words
Novella — 17,500 to 40,000 words
Novel — over 40,000 words
"...while the length of a novel is to a large extent up to its writer, lengths may also vary by subgenre; many chapter books for children start at a length of about 16,000 words, and a typical mystery novel might be in the 60,000 to 80,000 word range while a thriller could be over 100,000 words." [Wikipedia]