Red Blood Cell Count (RBC) Unit Converter

Red blood cell count (RBC) measures the number of red blood cells in your blood, expressed as millions of cells per microliter. Red blood cells, also called erythrocytes, are the most abundant cells in your blood.

These cells contain hemoglobin, an iron-rich protein that picks up oxygen in your lungs and delivers it to every tissue and organ in your body. Red blood cells also carry carbon dioxide back to your lungs to be exhaled.

Normal ranges differ by sex: men typically have 4.6-6.2 million cells per microliter, while women typically have 4.2-5.4 million cells per microliter. RBC count is usually part of a complete blood count (CBC) and is interpreted alongside hemoglobin and hematocrit.

Red blood cells are produced in the bone marrow through a process called erythropoiesis, which is regulated by the hormone erythropoietin (EPO) made primarily in the kidneys. Each red blood cell lives for about 100-120 days before being recycled by the spleen and liver.