Most of the college admissions essays have word count requirements, as do other questions on the applications. Do not ignore them. Stick to their numbers. If it says 500 words, make sure your essay is under that number. If nothing else, it shows you can follow directions.
If your essay is too long, start cutting. This is a great opportunity to actually make your essay better. My dad, a retired English professor, told his students that one way to gauge the best length of a piece of writing was to think of it as a woman’s skirt: keep it long enough to cover the material, but short enough to make it interesting. (No intention there to be sexist–the metaphor just doesn’t work as well for men’s shorts.)
Seriously, when you trim your essay, you almost always improve it. Read it for redundant words and sentences. A lot of times you will find you say almost the same thing in back to back sentences, even though you might have thought one supported the other.
The best place to start slicing is when you read your essay out loud and you hear for yourself where it starts to get dull or wordy. Trust yourself and cut it out! Also, go through your essay word for word and if you suspect you might not need a word, take it out. Is your meaning still clear? Then chop it!