Total testosterone
What it measures, and what changes the number.
Total testosterone measures all the testosterone in the blood, both the large share bound to SHBG and albumin and the small unbound share. Testosterone is produced mainly by the testes in males and in smaller amounts by the ovaries and adrenal glands.
It is often read with SHBG and albumin so that free or bioavailable testosterone can be calculated, and with LH and FSH, which reflect pituitary signalling. Estradiol and prolactin are frequently ordered in the same panel.
Levels vary over the day and are usually highest in the morning, so labs often request an early sample. The assay method matters: immunoassays (IA) and mass spectrometry (MS) can give different results, especially at lower concentrations, and results are reported in nmol/L or ng/dL. Labs may print it as TESTOSTERONE, TOTAL, MALES (ADULT), IA, TESTOSTERONE, TOTAL, MS or Testosterona total.
Reference ranges labs publish
Each lab states an interval for its own method and the population it measured. They differ, they are not interchangeable, and none of them is a verdict on a single result.
- Men, 19 years and over: 240 to 950 ng/dL (8.32 to 32.9 nmol/L) · LC-MS/MS · Established on morning specimens; the source notes early-morning levels in young men average 50% higher than afternoon levels · Source: Mayo Clinic Laboratories, TTST (Testosterone, Total, S) (read 2026-09-23)
- Men, 20 years and over: 264 to 916 ng/dL (9.15 to 31.8 nmol/L) · ECLIA (immunoassay) · Derived from non-obese men (BMI under 30) aged 19 to 39; the lab applies it unchanged from age 20 to over 80 · Source: Labcorp, 004226 (Testosterone) (read 2026-09-23)
- Men, 18 years and over: at least 250 ng/dL (no upper limit stated) (at least 8.67 nmol/L) · LC-MS/MS · Source: Quest Diagnostics, 15983 (Testosterone, Total, MS), FAQ165 (read 2026-09-23)
- Women, 19 years and over: 8 to 60 ng/dL (0.277 to 2.08 nmol/L) · LC-MS/MS · Established on morning specimens · Source: Mayo Clinic Laboratories, TTST (Testosterone, Total, S) (read 2026-09-23)
Usually reported in nmol/L or ng/dL.
Often read alongside: SHBG, Free testosterone (calculated), LH, FSH, Estradiol (E2)
Calculators that use it: Free testosterone calculator, Testosterone to estradiol ratio, Free androgen index (FAI)