Note that Stanford is on the quarter system, so it requires 180 quarter units to graduate (1 quarter unit = 2/3 semester unit, since a quarter is 2/3 as long as a semester).
According to http://csmajor.stanford.edu/ProgramSheets/CS_Unspec_1415PS.pdf , the CS major at Stanford requires:
26 units (14%) in math (including two math-for-CS courses in the CS department)
11 units (6%) in science (not CS)
13 units (7%) in engineering
43 units (24%) in CS
1 course (usually 4 units or 2%) in technology and society
The total for the CS major is 97 units, or 54% of the 180 units needed to graduate. (Looks like 4 is the most common credit unit value at Stanford, as it is at many other schools, but there are many 3 and 5 unit courses there.)