Grand Pianos 4-1/2' to 9-1/2' long		strings run horizontally hammers are below the strings and rise to hit them action sits on the back of the keys
Vertical Pianos Studio Upright:  over 42" tall Console:  40-42" tall		strings run vertically  hammers are in front of the strings and pivot back to hit them action sits on the back of the keys
Spinet (the smallest vertical piano) 36-38" tall		action hangs off the back of the keys.

To learn more about why it matters which direction the strings run, or how the hammers hit the strings, or whether the action sits on or hangs off the keys... click on "What's going on inside a piano?"