According to Real Female Bodybuilding, as of 2014, the biggest set of female biceps in the world are 20 inches and 20.25 inches respectively. These record-breaking biceps belong to extreme female bodybuilder Renne Toney. Her left bicep was the larger of the two, measuring 20.25 inches, or 51.4 centimeters.
Real Female Bodybuilding notes that Toney's record-setting biceps were measured in 2006 at the Arnold Classic Expo. As a 20-year professional bodybuilder, Toney took second place at the 1998 NPC Palm Springs Muscle Classic. She won both the 2002 World Physique Federation Pro Ms. Olympia Cup II and the 2004 World Physique Federation Pro Ms. Universe titles. As of 2014, Toney is retired from competitive bodybuilding.