What is a normal testosterone level by age, and what counts as low

For adult men, the American Urological Association treats a total testosterone below 300 ng/dL as the threshold for low, and a widely used harmonized reference range for healthy young men runs from about 264 to 916 ng/dL. Testosterone does fall gradually with age, but there is no official separate "normal" for a 60-year-old. A number only means something alongside how it was measured and how you feel.

Where the 300 number comes from

In 2018 the American Urological Association published its guideline on evaluation and management of testosterone deficiency. It set 300 ng/dL total testosterone as a reasonable cut-off for low, based on the levels at which symptoms became more likely in large studies. Two conditions come attached: the result has to be confirmed on a second early-morning test, and the man has to have symptoms or signs that fit.

The Endocrine Society's 2018 clinical practice guideline takes a similar approach with slightly different wording. It recommends diagnosing hypogonadism only in men who have symptoms and signs consistent with testosterone deficiency and unequivocally and consistently low serum testosterone. It refers to the harmonized range developed with the CDC, which puts the lower limit for healthy, non-obese men aged 19 to 39 at 264 ng/dL and the upper limit at 916 ng/dL.

Those two numbers, 264 and 300, are close, and both are starting points for clinical judgment rather than bright lines. A man at 310 with clear symptoms and low free testosterone may still warrant a closer look. A man at 280 who feels fine and has no signs of deficiency may not need treatment at all.

How testosterone changes with age

Testosterone peaks in late adolescence and early adulthood, then declines slowly. The Massachusetts Male Aging Study, one of the best-known long-term studies, followed men over several years and estimated that total testosterone fell by about 1.6% per year, while free and bioavailable testosterone fell faster, roughly 2% to 3% per year. Part of the reason free testosterone falls faster is that sex hormone binding globulin (SHBG) rises with age, binding more testosterone.

The decline is not the same for everyone. Weight gain, type 2 diabetes, poor sleep, sleep apnea, heavy alcohol use, opioid use and chronic illness all push testosterone down, often more than age itself. Healthy older men frequently have levels well within the young-adult range.

Total, free and the role of SHBG

Most testosterone in your blood is bound to SHBG or albumin. Total testosterone measures all of it. Free testosterone is the small unbound fraction, typically a few percent of the total, and it is the part most available to tissues.

When SHBG is unusual, total testosterone can mislead. Obesity and insulin resistance lower SHBG, so a heavier man may have a low-looking total with an adequate free level. Aging, liver disease, hyperthyroidism and some medicines raise SHBG, so an older man can have a normal-looking total with a low free level. The Endocrine Society recommends measuring free testosterone, by a reliable method or calculated from total testosterone, SHBG and albumin, when total testosterone is near the lower limit or SHBG is likely to be abnormal.

Free testosterone reference ranges vary more between labs and methods than total ranges do, which is one reason to interpret it with a clinician rather than against an online number.

Getting a result you can trust

Most misleading results come from how the test was done, not the lab itself. A few rules cover most of it:

• Test in the morning. Testosterone runs highest in the early morning, especially in younger men. Guidelines call for a sample taken in the morning, generally within a few hours of waking.
• Repeat it. One low result is a reason to repeat, not to treat. Illness, a bad night's sleep or recent heavy training can lower a single reading.
• Avoid testing while sick. Acute illness suppresses testosterone temporarily.
• Use an accurate assay. The Endocrine Society favors labs certified by the CDC Hormone Standardization Program or using mass spectrometry.

Our article on testosterone blood testing goes deeper into the extra tests, such as LH, FSH and prolactin, that explain why a level is low.

What about women?

Women make testosterone too, at much lower levels, typically in the range of tens of ng/dL rather than hundreds, with ranges depending heavily on the lab and assay. Standard assays are less accurate at those low concentrations. There is no agreed testosterone level that defines deficiency in women, and the 2019 Global Consensus Position Statement on testosterone for women advises against using a blood level to diagnose low libido or other symptoms. Blood tests in women are mainly used to establish a baseline and to make sure levels stay in the normal female range during any treatment.

What your number does and does not tell you

A low number with matching symptoms, confirmed on repeat morning testing, is the start of a diagnosis. The next step is finding out why, because conditions such as a pituitary problem, high prolactin, sleep apnea or medication effects change the treatment.

A normal number is not a reason to start testosterone, however tired or unmotivated you feel. The symptoms people associate with low testosterone overlap heavily with depression, poor sleep, thyroid problems and iron deficiency; see low testosterone symptoms for that overlap. And a declining number with age is not automatically a disease, which is the point of why TRT is not an anti-aging treatment.

If you have a result in hand and are unsure what it means, a physician can review it with your history and order what is missing. Our hormone therapy page explains how that evaluation works.

Questions patients ask us

What testosterone level is considered low?

The American Urological Association uses a total testosterone below 300 ng/dL as a reasonable cut-off, confirmed on at least two early-morning tests and paired with symptoms. The Endocrine Society refers to a harmonized lower limit of 264 ng/dL for healthy young men. Both are clinical starting points rather than strict lines, and lab reference ranges vary.

Is there a different normal testosterone range for older men?

Major US guidelines do not set separate diagnostic thresholds by age. Testosterone does decline slowly, and some labs print age-adjusted ranges, but the guidelines diagnose low testosterone using a single adult threshold together with symptoms. Many healthy older men have levels well within the young-adult range.

How fast does testosterone drop with age?

Gradually. The Massachusetts Male Aging Study estimated that total testosterone fell about 1.6% per year, with free testosterone falling faster, roughly 2% to 3% per year. Weight gain, diabetes, sleep apnea and chronic illness often push levels down more than age does. A gradual age-related decline is not, by itself, a disease.

Why does my testosterone need to be tested in the morning?

Testosterone follows a daily rhythm, highest in the early morning and lower later in the day, especially in younger men. An afternoon sample can read low in a man whose morning level is normal. Guidelines call for a morning sample, generally within a few hours of waking, and a repeat test if the first is low.

What is the difference between total and free testosterone?

Total testosterone measures everything in your blood, including testosterone bound to SHBG and albumin. Free testosterone is the small unbound portion most available to tissues. When SHBG is unusually high or low, as with aging, obesity or liver disease, total testosterone can mislead, and free testosterone helps clarify the picture.

My level is 350 ng/dL. Is that normal?

By the AUA cut-off of 300 ng/dL, 350 is in the normal range, but a single number is only part of the picture. If you have clear symptoms, a clinician may check free testosterone and SHBG, look for other causes of your symptoms and repeat the test. A normal result is not, by itself, a reason to start TRT.

Can a single low testosterone result be wrong?

Yes. Poor sleep, acute illness, recent intense exercise, some medications and an afternoon blood draw can all lower a single reading. That is why the AUA and Endocrine Society guidelines require at least two low early-morning results before diagnosing low testosterone. One low result means you should repeat the test.

What is a high testosterone level?

The harmonized reference range for young men tops out at about 916 ng/dL, and lab ranges vary. Naturally high levels are uncommon in men not taking testosterone. Levels well above range usually come from testosterone or anabolic steroid use, and on TRT the usual goal is the mid-normal range, not the top of it.

What is a normal testosterone level for women?

Women typically have testosterone levels in the tens of ng/dL, roughly a tenth to a twentieth of male levels, with ranges that depend on the lab and assay. Standard tests are less accurate at these low levels, and there is no testosterone level that defines deficiency in women.

Should I start TRT if my level is low but I feel fine?

Usually not. A diagnosis of hypogonadism requires both consistently low levels and symptoms or signs that fit. A low number without symptoms is still worth understanding, because it can point to a pituitary problem, a medication effect or sleep apnea, but treatment decisions are based on the whole picture, not the number alone.