Age difference between Marshall and Grant

[Gideon]

What would you estimate is the age difference between them?

(I want to know, because if I ever write any more stories about the characters in the future, I'd like to establish an age for Grant, to make an idea I have fit.)

[Menack]

Considering Grant says he graduated from BHH a few years ago, and that in Chemistry Marshall probably has around 2 years to go, I'd say it's around 5 years.

[Gideon]

Thanks, Menack!