Mean platelet volume (MPV) is a machine-calculated measurement of the average size of platelets found in blood and is typically included in blood tests as part of the CBC. Since the average platelet size is larger when the body is producing increased numbers of platelets, the MPV test results can be used to make inferences about platelet production in bone marrow or platelet destruction problems. A typical range of platelet volumes is 9.7–12.8 fL (femtolitre), equivalent to spheres 2.65 to 2.9 µm in diameter. Normal range is given as 7.5-11.5 fL.