Volume Formulas
cube = a 3
rectangular prism = a b c
irregular prism = b h
cylinder = b h = pi r 2 h
pyramid = (1/3) b h
cone = (1/3) b h = 1/3 pi r 2 h
sphere = (4/3) pi r 3
ellipsoid = (4/3) pi r1 r2 r3
Units
Volume is measured in "cubic" units. The volume of a figure is the number of cubes required to fill it completely, like blocks in a box.
Volume of a cube = side times side times side. Since each side of a square is the same, it can simply be the length of one side cubed.
If a square has one side of 4 inches, the volume would be 4 inches times 4 inches times 4 inches, or 64 cubic inches. (Cubic inches can also be written in3.)
Be sure to use the same units for all measurements. You cannot multiply feet times inches times yards, it doesn't make a perfectly cubed measurement.