Monocyte percentage, which refers to the proportion of monocytes in the total number of white blood cells, is calculated by dividing the number of monocytes by the total number of white blood cells to obtain a value that is converted into a percentage. Monocytes are a type of white blood cell. White blood cells in the blood include five types of cells: neutrophils, lymphocytes, eosinophils, basophils, and monocytes. A blood test can check the number of monocytes, the total number of white blood cells, and the percentage of monocytes. A normal person has a monocyte count of (0.12-0.8)x10^9/L and a monocyte percentage of 3%-8%. In certain infections and certain blood disorders, an increase in monocyte count and percentage can occur; a decrease in monocyte count and percentage is usually not clinically significant.