For adult men, a good testosterone level falls between 300 and 800 ng/dL, with most labs listing the full normal range as roughly 193 to 824 ng/dL. But that single number on your lab report only tells part of the story. Your age, the time of day your blood was drawn, and whether the test measured total or free testosterone all shape what “good” actually means for you.
The Standard Reference Range
Clinical labs generally consider total testosterone between 193 and 824 ng/dL normal for men aged 18 and older. The American Urological Association uses 300 ng/dL as its diagnostic cutoff: levels consistently below that, combined with symptoms, point toward testosterone deficiency. Harvard Health notes that some clinicians view 200 to 400 ng/dL as a borderline zone worth investigating further, while levels above 400 ng/dL rarely warrant concern.
These ranges vary slightly from one lab to another because different testing methods produce slightly different results. The number printed on your report matters less than how it compares to the specific reference range your lab provides.
How Testosterone Changes With Age
Testosterone peaks in the late teens and twenties, then declines gradually. Most men lose roughly 1 to 2 percent of their total testosterone per year after age 30. That slow slide means a man in his fifties can sit well within the normal range yet have noticeably less testosterone than he did at 25.
Bioavailable testosterone, the portion your body can actually use, shows this age-related drop more clearly. Mayo Clinic Laboratories lists these bioavailable ranges by decade:
- 20s: 83–257 ng/dL
- 30s: 72–235 ng/dL
- 40s: 61–213 ng/dL
- 50s: 50–190 ng/dL
- 60s: 40–168 ng/dL
A 55-year-old with a bioavailable testosterone of 90 ng/dL is right in the middle of his age-appropriate range, even though that same number would be low for a 25-year-old. Context matters more than chasing a single target number.
Total, Free, and Bioavailable Testosterone
Most testosterone in your blood is bound to a carrier protein called sex hormone-binding globulin (SHBG). While it’s attached to SHBG, your tissues can’t use it. A smaller portion binds loosely to another protein (albumin), and a tiny fraction floats freely. Free testosterone plus the loosely bound portion together make up “bioavailable” testosterone, the amount your body can readily put to work.
The Endocrine Society lists a normal free testosterone range of 50 to 200 pg/mL (picograms per milliliter, a much smaller unit than the ng/dL used for total testosterone). SHBG levels rise with age, meaning an older man can have a normal total testosterone reading while his bioavailable testosterone is genuinely low. This is why some clinicians recommend testing both total and free (or bioavailable) testosterone for a complete picture, especially in men over 50.
Conditions like obesity, liver disease, and thyroid disorders can push SHBG up or down independent of testosterone production. Certain medications do the same. If your total testosterone looks fine but you still have symptoms, a free or bioavailable testosterone test often reveals the mismatch.
Why Test Timing Matters So Much
Testosterone follows a daily rhythm, peaking shortly after you wake up and dropping as the day goes on. That decline is not subtle. Research published in the Journal of Neuroscience found that testosterone can fall by roughly 50 to 63 percent from morning to evening. A man who tests at 500 ng/dL at 8 a.m. might register under 300 ng/dL by late afternoon, producing a misleading result.
Clinical guidelines call for blood draws before 10 a.m., or within three hours of waking, preferably in a fasting state. Your sleep-wake pattern should also be stable, so testing right after a shift change or during jet lag can skew results. Because testosterone fluctuates day to day as well, a diagnosis of low testosterone requires two separate morning blood draws showing levels below the cutoff.
Symptoms That Signal a Problem
Numbers alone don’t determine whether your testosterone level is “good.” Two men at 350 ng/dL can feel completely different: one fine, the other struggling. The symptoms most closely tied to low testosterone are sexual. Reduced sex drive, loss of morning erections, and difficulty maintaining erections are the most specific warning signs.
Other symptoms that strongly suggest deficiency include shrinking testicles, loss of body hair (particularly armpit and pubic hair), hot flashes, and very low or absent sperm counts. Less specific but common complaints include depressed mood, difficulty concentrating, increased body fat, reduced muscle mass and strength, lower endurance, and breast tissue enlargement. Each of these can have other causes, which is why doctors look for the combination of low blood levels plus a cluster of symptoms before making a diagnosis.
“Normal” vs. Feeling Your Best
There’s an ongoing conversation in medicine about whether falling inside the reference range is the same as having an optimal level. The normal range for total testosterone spans from under 200 to over 1,000 ng/dL depending on the lab. That’s an enormous spread, and a man at 250 ng/dL is technically inside some reference ranges while clearly below the 300 ng/dL threshold most clinical guidelines use.
Some men with levels in the 300 to 400 ng/dL range report symptoms that improve when their levels are brought higher. Others at the same level feel perfectly fine. The Endocrine Society recommends that men over 50 with total testosterone between 200 and 400 ng/dL get additional testing, including free or bioavailable testosterone, before drawing conclusions. The goal isn’t to hit the highest number possible. It’s to land in a range where your symptoms resolve and your body functions well, without overtreatment.
Testosterone Levels in Women
Women produce testosterone too, just in much smaller amounts. Normal levels for women typically range from about 15 to 70 ng/dL, though the exact range varies by lab, age, and whether a woman is pre- or postmenopausal. Testosterone plays a role in bone density, muscle maintenance, mood, and sex drive in women. Levels that are too high can signal conditions like polycystic ovary syndrome, while levels that are too low may contribute to fatigue and reduced libido. The same principles apply: test in the morning, compare to the lab’s specific reference range, and interpret results alongside symptoms rather than in isolation.