formula question?

Amy • Wife ✨ Momma to a little girl & a little boy #3 on the way!
When you have 2 oz of water, you do a scoop and it makes it go up to 3 oz. and same with 4 oz of water and two scoops, to 5oz. Etc. My question is. Do you count the 2oz of water as 2oz of "formula" or 3oz?