GMAT

"Question: What's a Good Score on the GMAT Test?
Answer: Every business school program has a different understanding of what constitutes a "good" GMAT score, and there's usually not a fixed cut-off point required for admission. Admissions committees will also be looking at your past GPA and work experience, so you can think of your GMAT score as being balanced by those other considerations. Some schools may accept lower GMAT scores if you have a rich work history and a good past GPA; others may let you in because of high GMAT scores if you only have a few years of work experience.
Your first step should be to research the average GMAT test scores of the students who were accepted into the specific business schools you're interested in. Most schools publish these numbers online, so find them and take note of the average scores.
You should aim for a higher than average GMAT score to make yourself a competitive candidate for business school admissions.
Here's an idea of what you're up against: The most prestigious US business schools, including the Ivy Leagues, report that their students scored 700 on the GMAT on average. Less prestigious business schools, such as those at many state universities, report an average GMAT score of 550 - only slightly higher than the average score earned by all GMAT testers. In between those extremes, scoring 650 on the GMAT will beat the average and make you a competitive candidate at most business schools around the US.
So find out the average GMAT score for students accepted into the schools you're interested in, and target your test prep to match or beat that score.Business Week has 2 great resources that will help you understand the relationship between GMAT scores and schools:

An MBA Program Search to find the schools that would be the best match for you, considering your work experience, GMAT score, preferred state or region, and other factors.

MBA Program Profiles for most business schools in North America. Click on the schools you're interested in to learn the average GMAT score for accepted students in the past few years as well as the cost, the program length, and other vital information."