18” from countertops to bottom of upper cabinets.

There's a very recent thread on this exact question...search the Kitchens Forum. I'll aslo search for it

Everybody is really tall in our household. And we optimized our kitchen so that we use the lower cabinets a lot more than our uppers.

We ended up raising our countertops by 2" (i.e. 38" instead of 36"), and we raised our uppers by another 2" (i.e. 20" instead of 18"; or 58" from the floor). I personally like the extra height. I gives extra space where it is more useful to us. But I don't think I would go any higher than what we have. That uppers are definitely a little harder to reach, even though pull-outs help a lot.

I have a tall family, too. That is, except for me. I used to be "taller" (5'6 1/2") but I've shrunk. Unless you see yourself living in this house for at least the life of the kitchen, do the standard. You might have buyers who are short.

Here it is

https://www.houzz.com/discussions/5767588/what-space-should-i-leave-between-counter-top-and-bottom-of-upper-cabi#n=8