My 121cm upright piano keyboard is at 73cm from the floor (yes, it has wheels)
Coincidence, my Roland stage piano keys are also at 73cm from the floor when it is put on a regular RTX stand at the lowest setting.
However, I'm not sure this is standard !
I remember I had some problems with some stage pianos having lower keyboards (pb with my legs, not with my harms, assuming the bench is adjustable )
Fwiw, I measured the 3 pianos I have in my house. Top of a white key to the floor. Here's what I got:
console: 27 in
concert grand: 28.75 in
electric grand: 28.5 in
All are sitting on wall to wall carpet and the grand has its own Persian area rug in addition. The feet on the Yamaha electric have some adjustment to them but they're at minimum height. The concert grand has the brass factory installed wheels sitting on the stock 5.5 in diameter black coasters it came with. The Steinway console just sits on its rear rectangular wooden body which has small rollers hidden underneath.
In some less-classy concert, stage, and hotel settings, the piano might be left mounted on a triangular steel piano dolly with oversized heavy duty wheels. Very common in hotels. Where I've seen pianists ditch non-adjustable benchs in favor of a couple of stack chairs.