01 / Reference ranges
What counts as normal
Normal vs optimal
The harmonized range is 264 to 916 ng/dL for healthy nonobese men 19 to 39; the 5th to 95th percentile band is 303 to 852. Levels decline with age and with obesity, so a value in the 300s can be normal for one man and symptomatic for another. Marketing that promises an "optimal" level near the top of the range has no guideline basis: the guidelines treat symptoms plus a confirmed low value as the trigger, not distance from the top of the interval.
For women, the numbers on this page from Mayo Clinic Laboratories are a laboratory reference interval, not a guideline threshold.
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02 / Why it matters
What the number tells you
Two US guidelines govern how the number is read in men. The Endocrine Society (2018) recommends a fasting morning total testosterone with an accurate assay, confirmed by a second morning measurement, and points to the harmonized reference range for healthy nonobese men aged 19 to 39 of 264 to 916 ng/dL (Travison 2017), whose lower limit of 264 ng/dL applies to any CDC-certified assay. It also says free testosterone should be measured when total testosterone is modestly above or below the lower limit (about 200 to 400 ng/dL). The American Urological Association (2018, validity confirmed 2024) uses a total testosterone below 300 ng/dL as a reasonable cutoff in support of a diagnosis of low testosterone, and requires two early-morning measurements plus symptoms or signs. Neither guideline diagnoses on a number alone.
03 / In practice
Testing and what moves it
When it is tested
- Morning, fasting, on two separate days (Endocrine Society; AUA requires two early-morning measurements).
- Only when there are symptoms or signs of deficiency; population screening is not recommended.
- Use an assay certified against the CDC reference method where possible.
What raises it
- Morning sampling versus afternoon (about 50% higher in young men), testosterone therapy, some tumours (rare).
What lowers it
- Age, obesity, poor sleep and sleep apnea, opioids and glucocorticoids, acute illness, afternoon or non-fasting sampling, diabetes, pituitary or testicular disease.
04 / Related
Read next
Frequently asked questions
What is a normal testosterone level for a man?
The harmonized reference range for healthy nonobese men aged 19 to 39 is 264 to 916 ng/dL (Travison 2017), which the Endocrine Society adopts for CDC-certified assays. The AUA uses below 300 ng/dL as a cutoff that supports a diagnosis of low testosterone when symptoms are present.
Why do I need two tests?
Testosterone varies by time of day and from day to day, and food lowers it. Both the Endocrine Society and the AUA require two morning measurements before diagnosing deficiency.
Can I check testosterone at home?
At-home kits collect a finger-prick or saliva sample and send it to a lab. A blood test in the morning, on a certified assay, is what the guidelines describe; a saliva result or an afternoon sample cannot be read against the ranges above.
4 documents set the numbers on this page. The oldest was published in 2017, the newest in 2026.
- Travison et al., Harmonized Reference Ranges for Circulating Testosterone Levels in Men (JCEM 2017)
- Endocrine Society Clinical Practice Guideline: Testosterone Therapy in Men With Hypogonadism (2018)
- AUA Guideline: Evaluation and Management of Testosterone Deficiency (2018, validity confirmed 2024)
- Mayo Clinic Laboratories test catalog: Testosterone, Total and Free, Serum (reference interval, accessed 2026-08-19)
We last re-read these sources on . How we verify.