If you go into each schools thread, you will see the average GMAT Score for each school (e.g. 80th percentile)harvard-hbs-calling-all-applicants-class-of-151299.html
For HBS it is 723 as average and their 80th percentile split is 680 - 760, so as long as you are in the middle of that (720), you should be good but you may be able to get away with 680 if you are better than 90% of applicants.
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