Normal Testosterone Levels

A decline in testosterone generally starts in men from around 30 years of age. They are at their highest during adolescence or around 18-19 years old.

The gradual decline of testosterone is estimated more accurately at 1.6% per year and can affect sex drive amongst other things. In women, testosterone declines after menopause which is usually occurs around 45 to 55 years old.

Free or unbound testosterone which is around 2% of total testosterone declines at a higher rate of about 2-3% every year. 

As it declines over time, it makes sense that older men tend to have less testosterone than younger men. This leads to changes in the body, but the right answer is a healthy testosterone level. This can vary widely by individual. 

Levels can be impacted by age, size, and body shape. Lifestyle also has a significant impact, and depending on the time-of-day testosterone levels can fluctuate but are usually highest in the morning.

How to measure

• ng/dl – nanograms per decilitre
• nmol/l* – nanomoles per litre

*To convert: 1 nmol/litre = 28.85 ng/dl

Optimal testosterone

Normal levels can be controversial and tricky for the reasons listed above. Usually, the best indicator is a range for total testosterone, by age.

In males 19+ years of age, the range is 265ng/dl - 923ng/dl per MedicalNewsToday, while the University of Rochester gives a guideline range of 270ng/dl -1,000 ng/dl. See what we mean by tricky.

An Australian study of 21-35 year olds found the range to be 280ng/dl - 939ng/dl, with an average of 525ng/dl.

In the study below, the testosterone levels of 1,486 healthy, non-obese men in the age range of 20 to 44 years old (yo) were analysed.

These are the results by age and in ng/dl:

Keep in mind around 300ng/dl is considered to be a low testosterone level.

The American Urological Association (AUA) quotes T levels of at least 300 ng/dl for males and for women 19 years and older 15 to 70 mg/dl.

Find out more about low testosterone here, the signs and symptoms, and how age affects T levels. It is unlikely that you would have too much testosterone.

The testosterone level ranges for 40+ years are:

40-59yo  | Range 250ng/dl - 890 ng/dl

60yo+  | Range 250ng/dl - 720ng/dl

The lab we use to test our own testosterone levels gives a range for 55yo men of 150ng/dl - 590ng/dl.

So, don't focus on the NUMBER, focus on the MAN.

If you are worried. Get tested.

Great, so what next

Check out our low testosterone symptoms page to see if you have any, some, or many of the symptoms listed. If you decide you do have concerns, you can either:

1. Try a saliva test as an initial guideline.
2. See your doctor and request a blood test.

Test in the morning, ideally between 7am and 10 am, and follow any fasting or other instructions as directed.

The US FDA advise against RTR (Testosterone replacement therapy) for reduced levels of testosterone based on age related decline. If you feel you have low levels, then test or go see your doctor who can do a physical exam and request a blood test which is generally the most accurate.

Disclaimer: The information provided by Old Bull Health in this article is for informational purposes and should not replace professional medical advice. Our content is not intended to be medical advice, diagnosis, or treatment, and thus reliance should not be placed on it. If you are experiencing testosterone related symptoms, please consult a healthcare professional.