Normal total testosterone in adult men generally falls between 300 and 1,000 ng/dL, though the exact reference range varies slightly depending on the lab. Most medical guidelines consider levels consistently below 300 ng/dL a sign of testosterone deficiency, but that number alone doesn’t tell the full story. Your age, the time of day you’re tested, your weight, and whether you’re experiencing symptoms all factor into what “normal” actually means for you.
Total Testosterone Ranges by Age
Testosterone peaks in the late teens and early twenties, then begins a gradual slide. After age 30, levels decline by roughly 1% to 2% per year. That means a man in his 50s can have significantly lower testosterone than he did in his 30s and still be within a perfectly healthy range for his age group.
Here’s what the typical ranges look like by decade, based on Labcorp reference data:
- Age 40 to 49: 252 to 916 ng/dL
- Age 50 to 59: 215 to 878 ng/dL
- Age 60 to 69: 196 to 859 ng/dL
Notice how wide these ranges are. Two healthy 55-year-old men could have levels of 250 and 800, respectively, and both could feel perfectly fine. The range reflects natural biological variation between individuals, not just aging. A number near the bottom of the range isn’t automatically a problem if you have no symptoms.
Free Testosterone vs. Total Testosterone
The number on most standard blood panels is total testosterone, which includes all the testosterone circulating in your blood. But most of that testosterone is bound to proteins, primarily one called sex hormone-binding globulin (SHBG) and another called albumin. When testosterone is bound to SHBG, your body can’t readily use it. This binding is actually important for health; it prevents your body from using too much testosterone at once.
Free testosterone refers to the small fraction (typically 2% to 3%) that floats unattached to any protein. This is the form most available for building muscle, maintaining bone density, and supporting sexual function. Bioavailable testosterone is a slightly broader measure that includes free testosterone plus the portion loosely attached to albumin, which your body can still access relatively easily.
Why this matters: a man can have a normal total testosterone reading but low free testosterone if his SHBG levels are unusually high. SHBG tends to rise with age, so older men in particular may benefit from having free testosterone checked alongside total testosterone. The two measures are not interchangeable, and the American Urological Association notes there’s no clear, consistent threshold for free testosterone below which symptoms reliably appear.
Why Testing Time Matters
Testosterone follows a daily rhythm. Levels are highest in the early morning and drop as the day goes on. In men younger than 45, the swing is dramatic: mean levels in one study were around 600 ng/dL at 7 a.m., dropped to 500 ng/dL by 10 a.m., and fell to 400 to 450 ng/dL by 2 p.m. That’s a potential 25% to 30% drop from an early morning draw to an afternoon one.
This is why guidelines recommend testing in the morning, ideally before 10 a.m. An afternoon blood draw could produce a result that looks low simply because of normal daily fluctuation, not because of an actual deficiency. The Endocrine Society also recommends fasting before the test and confirming any low result with a second morning draw on a separate day before reaching any conclusions.
How Body Weight Affects Your Levels
Carrying extra weight has a well-documented effect on testosterone. Data from the Massachusetts Male Aging Study found that men who were obese had total testosterone levels averaging around 348 to 373 ng/dL, compared to roughly 422 ng/dL in men who were not obese. That’s a meaningful gap, and it held up even after adjusting for other health factors.
The relationship works in both directions. Men who became obese over the study period saw their levels drop, while the non-obese group maintained higher averages. Excess body fat increases the activity of an enzyme that converts testosterone into estrogen, which helps explain the link. For some men with borderline-low readings, losing weight can push testosterone back into a more typical range without any other intervention.
When a Low Number Actually Matters
A testosterone level below 300 ng/dL on two separate morning tests is the general threshold doctors use to diagnose deficiency, but the number alone isn’t enough. The Endocrine Society recommends making a diagnosis only when low levels are paired with actual symptoms. Those symptoms commonly include reduced sex drive, erectile difficulties, persistent fatigue, loss of muscle mass, increased body fat, depressed mood, and difficulty concentrating.
Some men with levels in the 200s feel fine, while others with levels in the low 300s feel terrible. There’s no single cutoff where symptoms switch on. The relationship between testosterone levels and how you feel is individual, which is why the clinical approach focuses on the combination of lab results and lived experience rather than treating a number in isolation.
If your levels come back low, expect your doctor to look for underlying causes before jumping to treatment. Obesity, sleep apnea, certain medications (especially opioids and corticosteroids), thyroid disorders, and pituitary gland problems can all suppress testosterone. Addressing these root causes sometimes resolves the deficiency on its own.