There is no "ideal" level of testosterone.

Measures of testosterone are highly individualized. There are clearly established abnormal levels but so-called normal levels are less generalizable. For starters, there is a high degree of variability in lab reference ranges with hundreds of points of difference on the low and high ends. What this means is that your level may be measured as normal by one lab and abnormal by another. Beyond that the range of normal is quite vast with the difference in high and low levels varying by almost 1,000 points in measurement. These degrees of variability alone make it difficult to assign meaning to any given measurement but there is more to it. When evaluating someone for possible low testosterone it is not only the lab measurement that matters but also the presence of symptoms. For example, one man with a testosterone level of 400 exhibiting many of the symptoms of low testosterone is very different from a man with a testosterone level of 400 who is thriving with no complaints. Beyond that, we also need to consider the potential for a change from baseline. It may be possible in the above scenario that the man with a level of 400 and symptoms may have experienced a significant change from baseline. This man may have been accustomed to living with a testosterone level of 700 which for one reason or another began to decline whereas the man without symptoms may have consistently lived at that level of 400. Another important aspect to consider is

if there are lifestyle aspects that might be driving hormonal dysregulation. An endurance athlete, due to their level of training will likely have some hormonal irregularities. Conversely, an obese man living a sedentary lifestyle likely would as well. Like many things, hormones rely on a goldilocks-like balance with issues arising when that balance is disturbed. These are some of the important factors to consider when evaluating a man’s testosterone level but by no means is an inclusive list. The moral of the story is there is no one-size-fits-all approach and no so-called perfect testosterone level.