MCHC: Abbreviation for mean cell hemoglobin concentration, which is the average concentration of hemoglobin in a given volume of blood. The MCHC is a calculated value derived from the measurement of hemoglobin and the hematocrit. (The hemoglobin value is the amount of hemoglobin in a volume of blood while the hematocrit is the ratio of the volume of red cells to the volume of whole blood.) The MCHC is a standard part of the complete blood count.