{"id":"testosterone-free","name":"Testosterone, Free","shortName":"Free Testosterone","aliases":["Testost., Free, Calc","Free Testosterone","Testosterone Free","Testosterone, Free, Direct","Testosterone, Free, Calculated","Testosterone, Free, Calculation","Testosterone Free, Calculation","Testosterone, Free (Dialysis)","Testosterone, Free by Dialysis","Testosterone, Free, Equilibrium Dialysis","Testosterone, Free, Equilibrium Ultrafiltration","Testosterone, Free, Mass Spectrometry","Testosterone, Free by Mass Spec","Free Testosterone, Equilibrium Dialysis","Testosterone, Free (Equilibrium Dialysis)","Free Testosterone (Calculated)","Calculated Free Testosterone","Free Testosterone, Direct","Free Testosterone, Serum","Dialyzable Testosterone","cFT"],"abbreviations":["cFT"],"loinc":[{"code":"2991-8","primary":true},{"code":"14914-6","primary":false},{"code":"103227-5","primary":false},{"code":"96559-0","primary":false},{"code":"49042-5","primary":false}],"specimen":"serum","units":[{"ucum":"pg/mL","display":"pg/mL"},{"ucum":"ng/dL","display":"ng/dL"},{"ucum":"pmol/L","display":"pmol/L"},{"ucum":"nmol/L","display":"nmol/L"}],"referenceRanges":[{"population":"Men, 18+","low":47,"high":244,"unit":"pg/mL","unitDisplay":"pg/mL","note":"ARUP calculated free testosterone (immunoassay total testosterone and SHBG, then a binding equation), adults 18 and older. Ranges depend heavily on the method, so compare only with a range for the same method. Other methods for adult men: Labcorp equilibrium dialysis 52-280 pg/mL; Labcorp equilibrium ultrafiltration 5.00-21.00 ng/dL (50-210 pg/mL); Labcorp direct analog immunoassay 6.6-26.5 pg/mL depending on age. Rows after the first five are method-specific alternatives.","sources":[{"title":"Testosterone, Free (Adult Males or Individuals on Testosterone Hormone Therapy) (test 0070111)","url":"https://ltd.aruplab.com/Tests/Pub/0070111","publisher":"ARUP Laboratories"},{"title":"Testosterone, Free, Mass Spectrometry/Equilibrium Dialysis (Endocrine Sciences) (test 500726)","url":"https://www.labcorp.com/tests/500726/testosterone-free-mass-spectrometry-equilibrium-dialysis-endocrine-sciences","publisher":"Labcorp"},{"title":"Testosterone, Free, Equilibrium Ultrafiltration With Total Testosterone, LC/MS-MS (test 070038)","url":"https://www.labcorp.com/tests/070038/testosterone-free-equilibrium-ultrafiltration-with-total-testosterone-lc-ms-ms","publisher":"Labcorp"},{"title":"Testosterone, Free, Direct (test 144980)","url":"https://www.labcorp.com/tests/144980/testosterone-free-direct","publisher":"Labcorp"}]},{"population":"Women, 18–30","low":0.8,"high":7.4,"unit":"pg/mL","unitDisplay":"pg/mL","note":"ARUP calculated free testosterone (total testosterone by mass spectrometry, SHBG by immunoassay), women 18-30. Other methods for adult women: Labcorp equilibrium dialysis 1.1-6.3 pg/mL; Labcorp equilibrium ultrafiltration 0.10-0.85 ng/dL (1.0-8.5 pg/mL); Labcorp direct analog immunoassay 0.0-4.2 pg/mL.","sources":[{"title":"Testosterone, Free (Adult Females, Children, or Individuals on Testosterone-Suppressing Hormone Therapy) (test 0081059)","url":"https://ltd.aruplab.com/Tests/Pub/0081059","publisher":"ARUP Laboratories"},{"title":"Testosterone, Free, Mass Spectrometry/Equilibrium Dialysis (Endocrine Sciences) (test 500726)","url":"https://www.labcorp.com/tests/500726/testosterone-free-mass-spectrometry-equilibrium-dialysis-endocrine-sciences","publisher":"Labcorp"},{"title":"Testosterone, Free, Equilibrium Ultrafiltration With Total Testosterone, LC/MS-MS (test 070038)","url":"https://www.labcorp.com/tests/070038/testosterone-free-equilibrium-ultrafiltration-with-total-testosterone-lc-ms-ms","publisher":"Labcorp"},{"title":"Testosterone, Free, Direct (test 144980)","url":"https://www.labcorp.com/tests/144980/testosterone-free-direct","publisher":"Labcorp"}]},{"population":"Women, 31–40","low":1.3,"high":9.2,"unit":"pg/mL","unitDisplay":"pg/mL","note":"ARUP calculated free testosterone (mass-spectrometry total testosterone), women 31-40. Compare only with a range for the same method.","sources":[{"title":"Testosterone, Free (Adult Females, Children, or Individuals on Testosterone-Suppressing Hormone Therapy) (test 0081059)","url":"https://ltd.aruplab.com/Tests/Pub/0081059","publisher":"ARUP Laboratories"}]},{"population":"Women, 41–51","low":1.1,"high":5.8,"unit":"pg/mL","unitDisplay":"pg/mL","note":"ARUP calculated free testosterone (mass-spectrometry total testosterone), women 41-51. After menopause ARUP uses 0.6-3.8 pg/mL. ARUP gives no age-based interval for women over 51 who are not postmenopausal.","sources":[{"title":"Testosterone, Free (Adult Females, Children, or Individuals on Testosterone-Suppressing Hormone Therapy) (test 0081059)","url":"https://ltd.aruplab.com/Tests/Pub/0081059","publisher":"ARUP Laboratories"}]},{"population":"Men, 18+","low":52,"high":280,"unit":"pg/mL","unitDisplay":"pg/mL","note":"Method-specific alternative. Labcorp (Endocrine Sciences): free testosterone by equilibrium dialysis with total testosterone by LC-MS/MS (1.5-3.2% free). Use this row only when your report says equilibrium dialysis.","sources":[{"title":"Testosterone, Free, Mass Spectrometry/Equilibrium Dialysis (Endocrine Sciences) (test 500726)","url":"https://www.labcorp.com/tests/500726/testosterone-free-mass-spectrometry-equilibrium-dialysis-endocrine-sciences","publisher":"Labcorp"}]},{"population":"Women, 18+","low":1.1,"high":6.3,"unit":"pg/mL","unitDisplay":"pg/mL","note":"Method-specific alternative. Labcorp (Endocrine Sciences): free testosterone by equilibrium dialysis (0.8-1.4% free). Use this row only when your report says equilibrium dialysis.","sources":[{"title":"Testosterone, Free, Mass Spectrometry/Equilibrium Dialysis (Endocrine Sciences) (test 500726)","url":"https://www.labcorp.com/tests/500726/testosterone-free-mass-spectrometry-equilibrium-dialysis-endocrine-sciences","publisher":"Labcorp"}]},{"population":"Men, 20–29","low":9.3,"high":26.5,"unit":"pg/mL","unitDisplay":"pg/mL","note":"Method-specific alternative. Labcorp direct analog enzyme immunoassay (test 144980). Guidelines advise against direct analog kits; use this row only when your report says 'Free, Direct'. Labcorp has no interval under age 20.","sources":[{"title":"Testosterone, Free, Direct (test 144980)","url":"https://www.labcorp.com/tests/144980/testosterone-free-direct","publisher":"Labcorp"}]},{"population":"Men, 30–39","low":8.7,"high":25.1,"unit":"pg/mL","unitDisplay":"pg/mL","note":"Method-specific alternative. Labcorp direct analog enzyme immunoassay (test 144980).","sources":[{"title":"Testosterone, Free, Direct (test 144980)","url":"https://www.labcorp.com/tests/144980/testosterone-free-direct","publisher":"Labcorp"}]},{"population":"Men, 40–49","low":6.8,"high":21.5,"unit":"pg/mL","unitDisplay":"pg/mL","note":"Method-specific alternative. Labcorp direct analog enzyme immunoassay (test 144980).","sources":[{"title":"Testosterone, Free, Direct (test 144980)","url":"https://www.labcorp.com/tests/144980/testosterone-free-direct","publisher":"Labcorp"}]},{"population":"Men, 50–59","low":7.2,"high":24,"unit":"pg/mL","unitDisplay":"pg/mL","note":"Method-specific alternative. Labcorp direct analog enzyme immunoassay (test 144980).","sources":[{"title":"Testosterone, Free, Direct (test 144980)","url":"https://www.labcorp.com/tests/144980/testosterone-free-direct","publisher":"Labcorp"}]},{"population":"Men, 60+","low":6.6,"high":18.1,"unit":"pg/mL","unitDisplay":"pg/mL","note":"Method-specific alternative. Labcorp direct analog enzyme immunoassay (test 144980).","sources":[{"title":"Testosterone, Free, Direct (test 144980)","url":"https://www.labcorp.com/tests/144980/testosterone-free-direct","publisher":"Labcorp"}]},{"population":"Women, 20+","low":0,"high":4.2,"unit":"pg/mL","unitDisplay":"pg/mL","note":"Method-specific alternative. Labcorp direct analog enzyme immunoassay (test 144980), women over 19. Analog kits are not accurate at women's low levels.","sources":[{"title":"Testosterone, Free, Direct (test 144980)","url":"https://www.labcorp.com/tests/144980/testosterone-free-direct","publisher":"Labcorp"}]}],"review":{"status":"ai-verified","label":"AI-verified against cited sources. Awaiting expert review","lastReviewed":"2026-10-03"},"summary":"The small part of your testosterone that isn't attached to proteins. Results depend heavily on the lab method, so compare only with a range for the same method.","url":"https://bloodtesttracker.com/markers/testosterone-free","notice":"Information, not medical advice. Ranges differ between labs, so the range on your own report is the one your result is judged against."}