Reference Range Free: 7.2 - 24.0 pg/mL max reportable: 50pg/mL Total testosterone does not have a numerical cap. Total Testosterone measures the amount of testosterone in your blood. This measurement represents the amount of T your body is producing. Free Testosterone measures the amount of testosterone that can be used by the body. Testosterone is a hormone produced in the body which helps to; Maintain reproductive tissues; Stimulate sperm production; Stimulate and maintain sexual function; Increase muscle mass and strength; Maintain bone strength; Decrease risk of disease and death.