Generally the maximum length for a short story is 5000 words. Yes, they can be longer - look at Alice Munro. But in terms of doing stuff with stories - entering competitions, getting published in magazines etc - you'll find 5000 words is the upper limit.
Most short story competitions usually give a maximum, not a minimum. 2000, 2500 or 3000 are common maximums, but there are competitions that stipulate a maximum of 1000.
Radio 4 short stories are usually 2200 - 2400 words - the length is dictated by the reading time available, 14 minutes.
If you're interested in writing for the women's magazine market you need to check each magazine's requirements as they change frequently, but generally a one page story will be 1000 words, two pages 2000. Therefore they only need 1000 word or 2000 word stories, not 1500 word ones. There are some magazines that carry longer stories, up to 3000 words, or shorter ones, usually around 800 words.
Flash fiction is an area I've not tried myself but it's for shorter stories, maximum 150 words. And there's also Twitter which ran a short story competition a few months ago, maximum 140 characters.
Generally, the most useful length is 2000-2500 words, enough space to get some depth, but with a limit on how much breadth. But as ever, don't worry about it while you're writing. Just get it written.