What is the regulation height for a pitchers mound?

Answer 1

According to Major League Baseball rules, the peak of the mound (where the pitching rubber sits) must be ten and 1/2 inches above the level of home plate (MLB Rule 1.04). The degree of slope from an area six inches in front of the rubber is one inch to one foot (this is in the direction of the plate), and must be uniform. The pitching rubber is legally defined in the rules as the "pitcher's plate".

Although the rules do not specifically say so, it stands to reason that the slope on the back of the mound must be steeper, since the mound is circular and the rubber is toward the back of the mound. The diameter of the mound is 18 feet.