Red blood cell indices

Mean corpuscular volume (MCV) is the average volume of a red blood cell and is calculated by dividing the hematocrit (Hct) by the concentration of red blood cell count.^{[citation needed]}

• ${\displaystyle {\textit {MCV}}={\frac {\textit {Hct}}{[{\textit {RBC}}]}}}$
• Normal range: 80–100 fL (femtoliter)

Mean corpuscular haemoglobin (MCH) is the average mass of haemoglobin contained in a single red blood cell, expressed in picograms (pg). It is calculated from the haemoglobin concentration and RBC count: MCH = HGB (g/dL) ÷ RBC (×10¹²/L) × 10. It is reported as part of the CBC red cell indices. ^[2]

MCH remained stable for up to 18 hours when stored at 4±1°C. After this period, significant changes were observed. ^[3]

• ↓ MCH (hypochromic): Iron deficiency anaemia, thalassemia ^[2]
• ↑ MCH (hyperchromic): Macrocytic anaemia (B12/folate deficiency), cold agglutinins ^[2]
• MCH parallels MCV closely in most situations; discordance may suggest specific conditions. ^[2]

Mean corpuscular hemoglobin concentration (MCHC) is the average concentration of hemoglobin per unit volume of red blood cells and is calculated by dividing the hemoglobin by the hematocrit. ^{[citation needed]}

• ${\displaystyle MCHC={\frac {Hb}{Hct}}}$
• Normal range: 32-36 g/dL

Red blood cell distribution width (RDW or RDW-CV or RCDW and RDW-SD) is a measure of the range of variation of red blood cell (RBC) volume, yielding clues about morphology.^{[citation needed]}

The reticulocyte production index (RPI) or corrected reticulocyte count (CRC) represents the true significance of the absolute reticulocyte count to provide some reflection of erythropoietic demand and supply. The immature reticulocyte fraction (IRF) goes a step further to cast more light on the same question.^{[citation needed]}