Pocket Testosterone Calculator

Pocket Testosterone Calculator is a mobile app to calculate the free testosterone and the bioavailable testosterone. Both of free and bioavailable testosterone are more accurately reflect the level of bioactive testosterone than does the sole measurement of total serum testosterone. The sex hormone-binding globulin (SHBG)-bound fraction is biologically inactive because of the high binding affinity of SHBG for testosterone. Free testosterone measures the free fraction. Bioavailable testosterone includes free plus testosterone that weakly bound to albumin.

Testosterone is a hormone produced by the human body. It’s mainly produced in men by the testicles. Testosterone affects a man’s appearance and sexual development. It stimulates sperm production as well as a man’s sex drive. It also helps build muscle and bone mass. Testosterone production typically decreases with age. Most circulating testosterone is bound to sex hormone-binding globulin (SHBG), which in men also is called testosterone-binding globulin. A lesser fraction is albumin bound and a small proportion exists as free hormone. Historically, only the free testosterone was thought to be the biologically active component. However, testosterone is weakly bound to serum albumin and dissociates freely in the capillary bed, thereby becoming readily available for tissue uptake. All non-SHBG-bound testosterone is therefore considered bioavailable.

All calculations must be re-checked and should not be used alone to guide patient care, nor should they substitute for clinical judgment. Disclaimer: please seek a doctor’s advice in addition to using this app and before making any medical decisions.