Double-check that the area of one of the object's sides and volume are measured in the same units. For example, if the area is in centimeters squared and the volume is in meters cubed, the volume would need to be converted to centimeters cubed.
Divide the volume of the object by the area of one of the sides to attain the thickness. Suppose that the side area was 40 square centimeters and the volume was 80 cubic centimeters. Then the value obtained for the thickness would be 2.
Place the correct units onto the thickness measurement as it is only one-dimensional. For example, if the area was square centimeters, the units of the objects thickness would be centimeters. In the example, the thickness would be 2 centimeters.