Ability to do simple calculation in custom charts?

Hi guys, maybe this is possible already, but I would like to be able to creat a chart of GKI - Glucose to Ketone Index where I take my Blood Glucose divide by the Ketone index (same units mml/dl) and chart it.
Possible?
I'm doing it in Excel at the moment and there are some posited ranges that are useful for tracking this relationship for those wanting to achieve specific goals.

https://nutritionandmetabolism.biomedcentral.com/articles/10.1186/s12986-015-0009-2#:~:text=The 'Glucose Ketone Index' (,the major circulating ketone body.