Calculated Free & Bioavailable Testosterone Calculator (Vermeulen Clinical Formula)
Calculate your true biologically active Free Testosterone (ng/dL and pg/mL) and Bioavailable Testosterone from Total Testosterone, Sex Hormone-Binding Globulin (SHBG), and Albumin using the gold-standard Vermeulen equilibrium formula.
Calculated Free Testosterone (ng/dL)
Calculator Inputs
Calculated Free Testosterone (ng/dL)
Free Testosterone in pg/mL
Percentage of Free Testosterone (%)
Bioavailable Testosterone (ng/dL)
Free Testosterone vs Bioavailable Testosterone (ng/dL)
Endocrine diagnostic standard recommended by the Endocrine Society and ISSAM for evaluating hypogonadism and androgen deficiency.
This tool is a mathematical wellness and fitness estimation model for general educational guidance only. The results do not constitute medical diagnosis, clinical advice, or treatment plans. Always consult a qualified physician or certified dietitian before starting any dietary regimen, exercise program, or making health decisions.
Calculation Methodology
Vermeulen Law of Mass Action: Uses the association constants of testosterone to albumin (Ka = 3.6e4 L/mol) and SHBG (Kshbg = 1.0e9 L/mol) to calculate unbound Free T and weakly bound Bioavailable T.
Frequently Asked Questions
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