How many key are on a piano?

Answer 1

The modern standard piano has 88 keys.

Different from your average piano...

There is also type of piano called a "Cottage piano" which is missing the top and bottom octave of a normal sized 88 key keyboard and hence has 64 keys. There are many other styles of piano with varying numbers of keys.

There are two Bösendorfer pianos that have more than 88 keys: the 7'4" Bösendorfer 225 has 92 keys, and the 9'6" Bösendorfer 290 has 97 keys. Those keys are finished differently from the regular keys so you don't accidentally play them--the fulltone keys are in matte black and the semitones are in white. The extended ranges of these pianos really have nothing to do with particular music in the repertoire; for example, they were not added to accommodate the organ music. No specialist would buy a Bösendorfer piano for the performance of organ music. The range is simply to enable the piano to be built with a larger soundboard, and therefore to produce a richer and more resonant sound. Bartok's Piano Concertos Nos. 2 and 3 played on any other piano will not sound quite right in comparison. A Bösendorfer 290 is well above $100,000. The neat thing here is that the low-register strings are resonant to the higher-register ones, so you get really nice bass tones out of these pianos.
Standard pianos have 88 keys.

Answer 2

Traditionally there are 88 keys on a piano, although there are pianos with different numbers of keys. hope this was helpful