Testosterone Levels by Age and Sex: What Is Normal?

There is no single testosterone number that is “normal” for every person. Levels differ by sex, age, time of day, health status, medications, laboratory method, and the proteins that carry testosterone in the blood. A result should be interpreted against the range from the laboratory that performed the test and the reason testing was ordered.

For men, a diagnosis of testosterone deficiency requires symptoms plus consistently low morning measurements. For women, testing is more often used to evaluate possible androgen excess, and low values alone do not define a recognized deficiency syndrome.

What does a testosterone test measure?

Testosterone circulates in several forms:

• Total testosterone includes testosterone bound to proteins plus the small unbound portion. It is the usual first test.
• Free testosterone is the unbound portion. It may help when total testosterone is borderline or binding proteins are altered.
• Bioavailable testosterone includes free testosterone plus the portion loosely bound to albumin. It is used less often.

Sex hormone binding globulin, or SHBG, strongly influences total testosterone. Obesity, thyroid disease, liver disease, diabetes, aging, oral contraceptives, and other factors can alter SHBG and change how a total result should be read.

Normal testosterone range for adult men

A widely cited harmonization study combined data from four large cohorts and calibrated measurements to a reference method. In healthy, nonobese men ages 19 to 39, the 2.5th to 97.5th percentile range was 264 to 916 ng/dL.¹

This is a research reference interval, not a universal treatment threshold. It was derived from a specific population and depends on assays calibrated to the same standard. The lower and upper limits printed by your laboratory may differ.

Guidelines also use clinical decision thresholds. These are not always identical to a laboratory reference interval. A clinician combines the measurement with symptoms, repeat testing, age, health, and the assay used.

Do testosterone levels decline with age?

Average testosterone tends to decline across adulthood, but age is only one factor. Obesity, chronic illness, medication use, sleep, and overall health can explain part of the difference between younger and older groups.

Age-specific internet charts often create false precision. They may combine different assays, populations, and sampling times, then present the averages as targets. A 55-year-old man should not be treated solely because his result is lower than the average for a 25-year-old.

The Endocrine Society recommends using accurate assays and rigorously derived reference ranges, and diagnosing hypogonadism only when symptoms are accompanied by unequivocally and consistently low levels.²

Normal testosterone range for women

Women naturally have testosterone at much lower concentrations than men. Accurate measurement is more difficult at these low levels, so the assay matters greatly.

In one study using liquid chromatography with tandem mass spectrometry, the total testosterone reference interval across women ages 20 to 80 was 0.35 to 1.97 nmol/L, about 10 to 57 ng/dL. The researchers found an age-related decline and produced separate ranges by age and menopausal status.³

Other laboratories may report different ranges. Oral contraceptives, hormone therapy, menstrual status, and health conditions can affect results. Read our guide to testosterone in women for the clinical context.

What is a normal free testosterone level?

Free testosterone is especially sensitive to the measurement method. Direct analog immunoassays can be unreliable. Equilibrium dialysis is generally considered the reference method, while calculated free testosterone may be useful when total testosterone, SHBG, and albumin are measured accurately.

A standardized equilibrium dialysis study in healthy, nonobese men reported a free testosterone range of 120 to 368 pg/mL for ages 19 to 39 and 66 to 309 pg/mL across all adult ages studied.⁴ These numbers apply only to a comparable method and population. Do not compare a result from a different assay directly with them.

Why laboratories report different ranges

Variation can come from:

• The assay technology and calibration
• The reference population used by the laboratory
• Age, sex, body composition, and health of that population
• Sample collection time and fasting status
• Differences in SHBG
• Whether total, free, or bioavailable testosterone was measured

A 2022 review emphasized accurate total testosterone measurement with a standardized method and, when needed, free testosterone measured by equilibrium dialysis. It also recommended at least two morning fasting samples for diagnosis.⁵

How low testosterone is diagnosed in men

A clinician does not diagnose hypogonadism from a chart alone. The usual process includes:

1. Identify compatible symptoms or signs.
2. Measure morning total testosterone with an accurate assay.
3. Repeat a low result on a separate morning.
4. Consider free testosterone when total testosterone is borderline or SHBG is altered.
5. Measure luteinizing hormone and follicle stimulating hormone to help identify the cause.
6. Evaluate medications, illness, sleep, nutrition, fertility goals, and other relevant factors.

Our complete article on how testosterone testing works walks through each step.

Symptoms matter, but they are not specific

Low libido, fewer spontaneous erections, infertility, reduced body hair, small testes, anemia, and low bone density can support an evaluation for male hypogonadism. Fatigue, low mood, poor concentration, and reduced gym performance have many possible causes.

Likewise, a result inside the reference range does not explain every symptom. A clinician may need to assess sleep apnea, thyroid disease, depression, medication effects, diabetes, cardiovascular disease, or another condition.

Frequently asked questions

Is 300 ng/dL low testosterone?

It may be near a clinical decision threshold used by some guidelines, but it cannot be interpreted alone. Symptoms, repeat morning results, the laboratory range, SHBG, free testosterone, and the cause all matter.

What is a good testosterone level by age?

There is no evidence-based “optimal” target for each birthday. Use the laboratory's validated reference interval and a clinical evaluation rather than an online age chart.

Can testosterone be low one day and normal the next?

Yes. Testosterone varies with time of day, sleep, illness, nutrition, exercise, and measurement variability. That is why a low result is usually repeated.

Can a normal total testosterone hide low free testosterone?

It can happen when SHBG is high. The reverse can also occur when SHBG is low. Free testosterone assessment may help when the total result and clinical picture do not match.

Bottom line

Testosterone ranges vary by sex, age, assay, laboratory, and health context. The best-known harmonized range for healthy young men is useful research context, not a self-diagnosis tool. Men need symptoms plus repeat low morning levels for a diagnosis, while women require a question-specific evaluation with an assay accurate at low concentrations.

Sources

1. Travison TG, et al. Harmonized Reference Ranges for Circulating Testosterone Levels in Men of Four Cohort Studies in the United States and Europe. Journal of Clinical Endocrinology and Metabolism. 2017.
2. Endocrine Society. Testosterone Therapy for Hypogonadism Guideline Resources.
3. Haring R, et al. Age-specific Reference Ranges for Serum Testosterone and Androstenedione Concentrations in Women Measured by Liquid Chromatography-Tandem Mass Spectrometry. Journal of Clinical Endocrinology and Metabolism. 2012.
4. Bhasin S, et al. Reference Intervals for Free Testosterone in Adult Men Measured Using a Standardized Equilibrium Dialysis Procedure. Journal of the Endocrine Society. 2022.
5. Jasuja R, et al. Accurate Measurement and Harmonized Reference Ranges for Total and Free Testosterone Levels. Endocrinology and Metabolism Clinics of North America. 2022.

Evidence reviewed August 2026. This article is educational and is not a substitute for individualized medical diagnosis or treatment.