**When does a high GMAT score make little to no difference?**

“At HBS, the difference between a 740 GMAT and 780 is probably not going to move the needle,” believes Sandy Kreisberg, a prominent MBA admissions consultant and founder of HBSGuru.com. “At Wharton and MIT, ultra GMATs are recognized and rewarded although hard to quantify. The difference between a 640 and 680 GMAT can be critical at many places, especially if the rest of your profile is likable. With a 680, you are meeting them half way. With a 640, you are asking for a big favor.”

**How does my total score correspond to my percentile rank?**

The percentile rank of your score shows you the percentage of tests taken with scores lower than you for the most recent three-year period. If your total score is a 690, it means you are in the 87th percentile. In other words, your total score is greater than 87% of all the people who took the GMAT in the past three years. Another way to look at it is this: You are among the top 14% of GMAT test takers. To see how other total scores correspond to your percentile rank, consult that table at left.

**How long do you have to take the test?**

The total exam takes slightly less time than watching the movie classic Gone With The Wind: three and one-half hours. You’ll have 75 minutes for the 41 questions in the verbal section, another 75 minutes for the 37 quant questions, and then 30 minutes each for the dozen questions on integrated reasoning and one topic covered in the analytical writing assessment section of the test.

**How much time should you set aside to study for the exam?**

Probably more than the average U.S. student spends. The median number of hours that students in India spend preparing for the GMAT is 100, and the median for test takers in China is even a bit greater. Compare that to European students, whose median is 60 hours, and U.S. students, whose median is just 40 hours.

In fact, GMAC reports that only 10 percent of American students taking the GMAT study as long as Chinese students. And the result: The mean GMAT score for Chinese test-takers was 591 in the 2013 testing year. And in the United States? Well, it was 528. Ouch!

As you might expect, there is a positive correlation between study hours and GMAT scores. If you want to score a 600 or higher on the GMAT, you may want to mentally prepare to study upwards of 100 hours for the test. GMAC says that the average number of study hours for test takers who scored 700 and above is 99 hours. Those who averaged 64 hours—the least charted by GMAC in a study—scored less than 400 on the exam.

**When should you take the GMAT?**

Here’s a little-known fact about the test. Younger test takers tend to outperform those who are older, mainly because they are more practiced at taking standardized tests. At the age of 20 or 21, the average GMAT score is 575. At 22 or 23, it’s 536, a drop of 39 points. So if you’re just out of college and think you might apply to business school in the near future, take the GMAT as soon as you can. You just have to be sure to apply to an MBA program within five years, after which most b-schools will not accept those scores.