For adult men, normal total testosterone falls between 193 and 824 ng/dL. For adult women, normal levels are below 40 ng/dL. But those numbers alone don’t tell you much without understanding how testosterone fluctuates throughout the day, changes with age, and what your body actually does with the testosterone circulating in your blood.
Normal Ranges for Men and Women
Testosterone is measured through a simple blood draw, and the results are reported in nanograms per deciliter (ng/dL). The broadly accepted reference range for men aged 18 to 99 is 193 to 824 ng/dL. That’s a wide window, which means a 30-year-old at 350 ng/dL and another at 750 ng/dL are both considered clinically normal, even though one has more than double the other’s level.
Women produce far less testosterone, with normal levels falling below 40 ng/dL. Testosterone still plays an important role in women’s bodies, contributing to bone density, muscle maintenance, and sex drive. Levels that climb above 40 ng/dL in women can signal conditions like polycystic ovary syndrome (PCOS) or adrenal gland disorders.
Keep in mind that normal ranges vary between labs. Different testing methods and equipment can shift the boundaries slightly, so you should always compare your result to the specific reference range printed on your lab report rather than a number you found online.
Total vs. Free Testosterone
Most testosterone in your blood is bound to proteins, primarily one called sex hormone-binding globulin (SHBG). Bound testosterone is essentially in transit and not available for your body to use. Free testosterone, the small fraction circulating unattached, is what actually enters cells and drives the effects you associate with the hormone: muscle growth, sex drive, energy, and mood.
The normal range for free testosterone in men is roughly 50 to 200 pg/mL (picograms per milliliter, a much smaller unit than ng/dL). This measurement matters because two men can have the same total testosterone number yet feel very different if one has significantly more SHBG tying up his supply. A man with a total level of 500 ng/dL but high SHBG might have less usable testosterone than a man at 400 ng/dL with lower SHBG. That’s why many clinicians now place greater emphasis on free testosterone when evaluating symptoms.
If your total testosterone comes back in the low-normal range and you’re experiencing symptoms, asking for a free testosterone measurement can give a more complete picture.
How Testosterone Changes With Age
Testosterone peaks in the late teens and early twenties, then gradually declines. After about age 30, most men lose roughly 1% of their total testosterone per year. That means a man in his 50s will typically have noticeably lower levels than he did in his 20s, and both readings can fall within the normal range.
This steady decline is a normal part of aging, not a disease. It becomes clinically relevant only when levels drop low enough to cause symptoms. A 60-year-old sitting at 250 ng/dL who feels fine is in a different situation from a 60-year-old at the same level who is losing muscle mass, gaining body fat, and struggling with fatigue. The number by itself is not a diagnosis.
When Low Testosterone Is a Problem
A lab value below the reference range doesn’t automatically mean something is wrong, and a number inside the range doesn’t guarantee everything is fine. Diagnosis depends on a combination of blood work and symptoms. Common signs of low testosterone in men include:
- Low sex drive or difficulty getting erections
- Loss of muscle size and strength despite consistent exercise
- Increased body fat, particularly around the midsection
- Bone loss, which can increase fracture risk over time
- Fatigue and trouble concentrating
- Mood changes, including depression or irritability
- Sleep problems like insomnia
- Low sperm count
Some men with low levels on paper have no symptoms at all. Others experience several of these at once. Before attributing symptoms to low testosterone, your provider will typically rule out other explanations that look similar, including thyroid disorders, depression, medication side effects, and poor sleep quality. These conditions overlap heavily with the symptom profile of low testosterone and are sometimes the actual culprit.
How to Get an Accurate Test
Testosterone follows a daily rhythm: it peaks in the early morning and drops throughout the day, sometimes by 20% or more by afternoon. To get a reliable measurement, blood should be drawn in the morning, ideally before 10:00 AM or within three hours of waking up. Testing in the afternoon can give you a misleadingly low result.
Fasting before the test is also recommended. Eating, especially a high-fat meal, can temporarily lower testosterone readings. If you’re testing because you suspect a problem, getting the blood drawn early and on an empty stomach gives you the most accurate baseline.
One low result is not enough for a diagnosis. Testosterone fluctuates from day to day based on sleep, stress, illness, and other factors. A single reading below normal should be confirmed with a second test on a different morning before any conclusions are drawn. If both come back low and you have symptoms, that’s when the conversation about treatment typically begins.
What Affects Your Levels
Beyond age, several everyday factors push testosterone up or down. Sleep is one of the biggest: men who consistently get fewer than five or six hours a night can see testosterone drop significantly. Obesity has a similar effect, as excess body fat increases the conversion of testosterone into estrogen, effectively lowering your circulating supply. Losing weight often raises testosterone without any other intervention.
Chronic stress elevates cortisol, which competes with testosterone production. Heavy alcohol use suppresses it. On the other hand, resistance training, adequate protein intake, and consistent sleep hygiene all support healthy levels. None of these lifestyle changes will take a clinically deficient man back to the high end of the range, but they can meaningfully shift borderline numbers and improve how you feel regardless of what the lab report says.