A healthy testosterone level for adult men falls between 193 and 824 ng/dL (nanograms per deciliter), according to standard lab reference ranges. That’s a wide window, and where you land within it depends on your age, the time of day your blood was drawn, and how much of that testosterone your body can actually use. Understanding what the numbers mean, and what “normal” really looks like, matters more than chasing a single target.
Normal Ranges for Men
The general reference range for total testosterone in men aged 18 to 99 is 193 to 824 ng/dL. Most labs use a similar window, though the exact boundaries can shift slightly depending on the testing method. A man at 250 ng/dL and a man at 750 ng/dL are both technically “normal,” but they may feel very different. The number that matters is the one where your body functions well: steady energy, healthy muscle maintenance, normal sex drive, and stable mood.
The American Urological Association uses 300 ng/dL as a clinical cut-off. Below that threshold, a doctor may begin evaluating you for testosterone deficiency, provided symptoms are also present. A reading of 310 ng/dL doesn’t guarantee everything is fine, and a reading of 280 ng/dL doesn’t automatically mean something is wrong. The number is a starting point for a conversation, not a diagnosis on its own.
How Testosterone Changes With Age
Testosterone peaks in the late teens and early twenties, then gradually declines. Most men lose roughly 1 to 2 percent of their total testosterone per year starting around age 30. That means a man in his 60s will typically have significantly lower levels than he did in his 20s, and this is a normal part of aging, not necessarily a medical problem.
Because of this natural decline, a 65-year-old with a level of 350 ng/dL is in a very different situation than a 25-year-old with the same number. Labs don’t always adjust their reference ranges by age, so it’s worth knowing where you fall relative to others your age, not just relative to the full 193-to-824 range. Your doctor can help contextualize the result.
Total vs. Free Testosterone
When you get a standard testosterone blood test, the result is your total testosterone. But not all of that testosterone is available for your body to use. Most of it travels through your bloodstream bound to proteins, primarily one called SHBG (sex hormone-binding globulin). Testosterone that’s bound to SHBG can’t interact with your tissues. Only the unbound, or “free,” portion actively supports functions like muscle growth, bone density, and reproductive health.
The normal range for free testosterone is roughly 50 to 200 pg/mL (picograms per milliliter). You can have a total testosterone level that looks fine on paper while your free testosterone is actually low, because too much of it is locked up by SHBG. This is especially common in older men, since SHBG levels tend to rise with age. It also happens with certain liver conditions, thyroid issues, and some medications. If your total testosterone is in the lower-normal range and you still have symptoms, your doctor may order a free testosterone test to get a clearer picture.
The reverse is also true. Low SHBG means more of your testosterone is free and active. This can happen with obesity, type 2 diabetes, or certain metabolic conditions. In that case, your total number might look low, but your body is actually using a normal amount.
Why Testing Timing Matters
Testosterone levels aren’t static throughout the day. They’re highest in the morning and drop as the day goes on, sometimes by 20 percent or more by late afternoon. Clinical guidelines recommend drawing blood before 10:00 AM, or within three hours of waking up, ideally in a fasting state. A test taken at 3:00 PM could return a result that looks low simply because of normal daily fluctuation.
Even under ideal conditions, your levels can vary by 10 to 15 percent from one blood draw to the next due to normal biological variation. Two tests taken a week apart on the same person can differ by up to 30 percent. This is why clinical guidelines require at least two separate morning blood draws before diagnosing low testosterone. A single test is not enough to confirm a deficiency.
Signs Your Levels Are Where They Should Be
Healthy testosterone supports a cluster of functions you’d notice in daily life. Consistent energy levels, the ability to build and maintain muscle with regular exercise, a sex drive that feels normal for you, stable mood without unexplained irritability or depression, and adequate bone strength are all markers that your testosterone is doing its job. You won’t “feel” a specific number, but you’ll notice when these systems start to falter.
Low testosterone tends to show up as a combination of symptoms rather than a single red flag. Persistent fatigue that doesn’t improve with sleep, loss of muscle mass despite staying active, reduced sex drive, difficulty concentrating, and increased body fat (particularly around the midsection) are common complaints. None of these symptoms alone confirms a testosterone problem, since they overlap with dozens of other conditions. But if several are happening at once, testing is a reasonable next step.
What Pushes Levels Too Low or Too High
Beyond aging, several factors can suppress testosterone. Poor sleep is one of the most potent. Men who consistently sleep fewer than five hours per night can see testosterone levels drop by 10 to 15 percent. Obesity has a similar effect: excess body fat increases the conversion of testosterone into estrogen, creating a cycle where low testosterone promotes more fat storage, which further lowers testosterone. Chronic stress, heavy alcohol use, and certain medications (particularly opioids and corticosteroids) also suppress production.
Abnormally high testosterone is less common outside of supplementation or anabolic steroid use. In those cases, the body may respond by shrinking the testes (since they no longer need to produce testosterone on their own), developing acne, or increasing red blood cell counts to potentially dangerous levels. Naturally elevated testosterone within the reference range is not a concern.
Getting Tested
A testosterone test is a simple blood draw, typically ordered as part of a hormone panel. To get the most accurate result, schedule the draw for early morning, fast overnight if possible, and avoid intense exercise the day before (heavy training can temporarily spike levels). If the first result comes back low, expect your doctor to order a second test on a different day before making any treatment decisions. That two-test requirement exists precisely because single readings are unreliable.
If both results fall below 300 ng/dL and you have symptoms, your doctor will likely check additional markers: free testosterone, SHBG, and hormones from the pituitary gland that signal the testes to produce testosterone. These help distinguish between a problem in the testes themselves and a signaling issue higher up in the hormonal chain, which changes the treatment approach significantly.