Please Excel nerds, can you tell me how to get the sum of all values in one column which have the same value in another column? Lecturers have students in different classes and I want to know how many students they have in total. e.g.

Name | Number of Students

Smith | 20

Smith | 25

Jones | 15

Jones | 10

Jones | 7

Brown | 5

Brown | 20

Is it possible to have a single formula in a column which will do this? There are about 380 staff teaching about 2,000 classes.