Yeah, there are, but for a bar, there's sometimes differences, and a lot of times, we work off of that stuff I asked him....seating at a bar requires a different height (sometimes not, though, if they've already bought chairs) than standing, and sometimes, depending on the chair, something different from THAT, even! For instance, my bro-in-law has Hair Salon chairs for seating around his bar, and they sit WAY lower than standard bar stools. They CAN be pumped up to standard bar height, but the seating was WACK for that, so it's actually lower than normal.
Between 36"-38" and 40-42" is the standard, and it'll depend more on your preferences, as you should be able to find chairs for any of those. The lower figures (36 & 40) are the "standards" but we tend to find the higher figures (38 & 42) seem to be chosen more often, actually, and the comment "geez, I hate when I'm at so-and-so's house...I always feel like I'm leaning over" is what generally follows. We ALWAYS do a fake countertop and have them sit at it to find out, though. Some sawhorses with a few 1 by's or shims will suffice, and build it for yourself (same as a cab) not for all the people you think may or may not like it.