I'm not a tall guy but the chair doesn't extend very high certainly not tall enough for my desk. It was impossible to determine that when I purchased it at the store. Kind of out of luck.
I’ve enjoyed the chair so far and the multiple adjustment options make it nearly a winner. Its one minus is seat comfort. I found it to be harder than anticipated. Fortunately I had a nice seat pad I used on an old chair which is making it much more tolerable.