<p>As bonanza explained, the number of graduate students is a complicated issue. Looking at the number of graduate students at my alma mater (8000), you’d think undergraduates are greatly outnumbered there. You must consider, however, what that number contains – law students, medical students, business students, nursing students, divinity students, etc. Each of these professional schools has its own professors, administration, career center, library, dining facility, building(s), etc. In terms of the overall size of the university - the number of people who will be bustling about on campus - yes, all of these may be worth consideration. </p>
<p>When thinking about things relevant to your education, which includes things like time with professors, research opportunities, lab space, etc., you need to worry more about the ratio of undergraduates to graduate students in relevant fields like arts & sciences and/or engineering, since those are the students with which you’d be competing.</p>
<p>The undergraduate:graduate ratios in arts & science and engineering for the top 20 universities are listed below. Where possible, I separated them into separate listings.</p>
<p>Engineering
Stanford Engineering 0.26:1
JHU Engineering 0.52:1
Columbia Engineering 0.63:1
Yale Engineering 0.86:1
Penn Engineering 1.07:1
Dartmouth Engineering 1.10:1
Harvard Engineering 1.23:1
Duke Engineering 1.60:1
Cornell Engineering 1.73:1
Rice Engineering 1.80:1
Princeton Engineering 1.83:1
Brown Engineering 2.67:1
Vanderbilt Engineering 3.14:1
Northwestern Engineering 4.86:1
WUStL Engineering 6.26:1</p>
<p>Mixed A&S/Engineering
MIT 0.67:1
Caltech 0.78:1 </p>
<p>A&S
JHU A&S 1.11:1
Northwestern A&S 1.38:1
Chicago 1.52:1
Harvard A&S 1.73:1 (2.07:1 without Medical Science)
Yale A&S 1.98:1
Stanford A&S 2.05:1
Columbia A&S 2.07:1
WUStL A&S 2.17:1
Vanderbilt A&S 2.24:1
Princeton A&S 2.35:1
Duke A&S 2.58:1
Penn A&S 2.89:1
Rice A&S 2.98:1
Cornell A&S 3.51:1
Brown A&S 4.33:1
Dartmouth 6.91:1</p>
<p>I excluded Notre Dame because I couldn’t find a good breakdown of its enrollment statistics and Emory because Oxford complicates things.</p>