Probably the most common questions I get are:
1) Are my testosterone levels normal for a male?
2) What should male testosterone levels be?
Well, normal is relative as we all know. But, even so, we can come up with some solid guidelines that will help you know where you stand.
However, I first want to encourage you to throw out the completely lame and utterly useless ï¿½normalï¿½ range that your doctor or lab technician will give you. A typical normal male testosterone level range given is 260 -1080 ng/dl as (which corresponds to about 8.8 - 36.7 nmol/l). Well, to that I can only say that you can call any level you want normal, but 260 is nothing but ugly. In fact 300 and 350 are ugly testosterone levels for a male. Virtually every email that I get where a guy is struggling is from some guy with total testosterone under 400 ng/dl. And younger guys, again based on numerous emails that I have received, struggle with testosterone less than 500. I have never received any email from someone complaining with testosterone levels over 500.
CONVERSION FACTORS: On this page I am only talking about total testosterone and in all cases I use values given in ng/dl. If you want to convert to, say, nmol/l, you must use a conversion factor of 29.4 or .034 going the other direction. Yes, that high school chemistry may pay off for you if youï¿½re from a country or reading a journal article that uses moles. If you are interested in normal free testosterone levels, please see this link on Free Testosterone.
So the normal testosterone pain threshold is about 500, depending on a maleï¿½s age and history. (Below 400 is almost always a free pass to hormonal hell.) That is why I am so disgusted with the medical profession when they tell one of my fellow male brothers that a total testosterone level of 290 is fine and normal. (Please read my link on Testosterone Symptoms if you do not know how dangerous low testosterone levels are to your health.)
That said, I want to make several important points about male testosterone levels and lab readings. First of all, you should keep in mind that itï¿½s unwise to go by one reading, because your testosterone fluctuates considerably from week to week and even from day to day. Stress, lack of sleep and many other things that are a normal part of life for us males ï¿½ see my link Common Things That Lower Testosterone ï¿½ can whack testosterone levels. It is entirely possible, for example, for your testosterone to be 400 one week and 525 the next. Lifestyle issues can whack even normal testosterone 20-30% or more.
You should also try to get your testosterone levels read in the morning if at all possible. Male testosterone levels peak in the morning and then steadily decline until late evening. This decline from am to pm is, on average, about 35% for most younger guys and about 10% for seniors. (See my link on Daily Testosterone for more information.)
In addition, itï¿½s worth pointing out that labs arenï¿½t perfect either. I had one testosterone reading that was three times any previous reading that I had ever received! Of course, there is no reasonable explanation for that reading and it was surely an outlier from normal as they say in the stats world.
All cautions aside, though, we can come to some conclusions and you can assess your testosterone levels against the average for males. For example, there was a 1999 study that examined 4,393 men between the ages of 32 and 44 and found that their average testosterone level (at 8 a.m.) was 679 ng/dl.  It should be noted that in this study the men with testosterone levels slightly above 800 were 42% and 72% less likely to have high blood pressure and a heart attack, respectively, than those with testosterone a little less than 400. Again, solid testosterone is good for you!
So you may be wondering what exactly are normal male testosterone levels? Well, again, letï¿½s go to another study, the NERI (New England Research Institute) study.  This study examined, amoung other things, men in the age bracket of 65-69 and found that in 1988 average testosterone levels were 503 ng/dl but in 2003, fifteen years later, the average levels had fallen to 423. This corresponds to what other studies have found: testosterone levels are falling steadily with time. I speculate that the leading factors for such a decline are diet, mitochondrial damage, excitoxins and pesticides. See my links to the left for more information on what can sabotage normal testosterone. Or maybe you just watch too much Barney as a kid - I don't know.
So if you put these studies together you can start to get a good picture of reasonable values by age. Studies have found that total testosterone levels decrease, in the average male, by about 1.0-1.2% per year and free testosterone by about 1.2-1.3% per year. This decline, by the way, is normal and a part of aging the great majority of us guys. What you don't want is to venture significantly below these normal numbers - low testosterone is "nuthin' but trouble" for us males.
NOTE ABOUT EXCITOTOXINS: Some researchers, suspecting excitotoxin damage, have shown evidence of rates greater than this in the last two decades. Read here for evidence of Rapid Excitoxin Damage and my link on Testosterone and Excitotoxins as well.
Even so, let me throw out an "average" testosterone level table by age to start out with simply by starting with a peak of 700 and decreasing by 50 ng/dl each decade:
As a verification, one can look at this link and find a normal or average testosterone level chart by age. 
|Avg Age||Tot. Test.|
If you do enough research, you will find other similar results and average values can indeed get a good feel for the age-related decline in testosterone levels.
Now let's jump to some important points when comparing your numbers to these kind of average or "normal" male testosterone levels. First of all, you must remember not to panic if your testosterone is a little below what is given above. For example, there are many guys with testosterone in the 400's that are doing great with solid libido, erections and heart health. In fact, guys like this probably have no idea that their testosterone is below "normal" and are doing just fine.
Although let me jump in and say that many young guys have written in that are struggling with testosterone levels in the 400's as I mentioned. Young males seem to be particularly sensitive or perhaps it's the relative value compared to age that really counts. Regardless, I have known several younger guys who have reported dramatically improved erections and libido when given supplemental testosterone even though they were in the 400's and were supposely "normal". (Giving young men TRT is a questionable practice, however, and some doctors will not do it but will instead use alternative therapies that we discuss elsewhere in this book.)
So if your testosterone level is below average, regardless of whether you as a male are experiencing classic Low Testosterone Symptoms, , you may want to natural methods, dietary and lifestyle factors, that can naturally boost. I cover many dietary and lifestyle factors on my site that can naturally boost testosterone. Read this link, for example, on How to Boost Your Testosterone Naturally. And, yes, that even includes Sex! It may be possible to boost your testosterone levels 20-40%, and possibly get them into the normal and acceptable range, simply by changing certain lifestyle factors.