Normal Testosterone Levels in Men & Women: Total, Free, & Bioavailable Testosterone

Testosterone is roughly 25 times higher in men than women and is responsible for regulating the male reproductive system, muscle growth, energy levels, immunity, and much more. 

Testosterone plays an important role in women as well, where it serves as the precursor molecule for estrogen. 

It’s normal for testosterone levels to change as we age. 

In men, peak levels are reached around 19 years of age, and gradually start to decline by 40. 

Women have much lower testosterone levels on average, and testosterone levels can fluctuate on a monthly basis. 

In this article, we’ll cover everything you need to know about normal testosterone levels in both men and women. 

We’ll cover the different ways we can measure testosterone (free, total, and bioavailable), and cover the optimal levels depending on your age and gender. 

What Are the Normal Testosterone Levels in Men?

The normal range of testosterone in adult males is 10 – 41 nmol/L (300 – 1200 ng/dL). 

This range represents the amount of total amount of testosterone in the blood. 

When a man tests lower than 10 nmol/L or 300 ng/dL total testosterone, he’s considered to be testosterone deficient. 

Total testosterone scores have long been used to help doctors assess male reproductive health, but there are better metrics applied today that paint a clearer picture.

Total Testosterone vs. Free Testosterone

Over 97% of testosterone in a man’s body is bound to proteins like albumin and SHBG (sex hormone-binding globulin). 

These proteins retain testosterone in an inactive form. The body uses SHBG to control the amount of testosterone the cells have access to.

Free testosterone is a measurement for testosterone not bound to any of these proteins. Only around 0.5%–3% of testosterone is found in its free form [2]. 

A lot of older men have elevated levels of SHBG, which can reduce the amount of free testosterone in the bloodstream. 

The problem is that if total testosterone levels are the only metric tested, the results would appear normal — yet the amount of free, active testosterone may be much too low.

The normal range of free testosterone levels in men is 0.3 – 1.0 nmol/L. 

Free Testosterone vs. Bioavailable Testosterone

An even better metric to consider is the amount of bioavailable testosterone. This looks at the amount of free testosterone plus the amount of albumin-bound testosterone. 

Albumin has a weak binding action to testosterone, which makes it easy for the body to knock the testosterone free and make it available for the cells. The testosterone bound to albumin is still considered active — while testosterone bound to SHBG is not active. 

On average, 40% of protein-bound testosterone is linked to SHBG, while the remainder is bound to albumin [3].

Today, most doctors use bioavailable testosterone as the key metric for assessing healthy levels in men of all ages. 

The normal range of bioavailable testosterone in men is about 3 to 8 nmol/L. 

As men age, the normal range of bioavailable testosterone naturally begins to decline over time. By age 70, bioavailable testosterone can reach as low as 1.4 nmol/L and still be considered normal.

Normal Testosterone Levels in Men by Age

Testosterone levels surge during infancy, drop off for a few years, and then spike back up to peak levels during puberty. 

After puberty, testosterone levels remain stable for 10 – 20 years. 

Around age 30 or 40 testosterone levels will gradually deplete at a rate of around 1% per year. 

Here, we’ll cover the normal testosterone ranges by men at different stages of life. We’ll cover all three forms of testosterone (total, free, and bioactive). 

Keep in mind; these are the normal ranges for most people. Someone can have testosterone levels outside the standard range and still be healthy. Normal simply refers to the average for most people. 

References used: Mayo Clinic Labs, Kelsey et al., 2014, McBride et al., 2015.

1. Normal Testosterone Levels in Children

In the first 5 months of life, baby boys have very high testosterone levels, which is used to stimulate the development of male genitalia. 

After the 5-month mark, testosterone levels drop for about 12 or 13 years until puberty.

Age RangeTotal TestosteroneBioavailable TestosteroneFree Testosterone
0 – 5 months2.60 – 13.88 nmol/L(75 – 400 ng/dL)N/A<0.01 – 0.11 nmol/L(0.20 – 3.10 ng/dL)
6 Months – 9 Years0.24 – 0.69 nmol/L(7 – 20 ng/dL)N/A<0.01 – 0.01 nmol/L(0.04 – 0.45 ng/dL)
10 – 11 Years0.24 – 4.51 nmol/L(7 – 130 ng/dL)N/A<0.01 – 0.19 nmol/L(0.04 – 5.52 ng/dL)

2. Normal Testosterone Levels In Teenagers

During adolescence (11 – 13), testosterone levels start to rise once again. This triggers the many changes associated with puberty. It stimulates muscle growth, deepens the voice, increases the size of the testes and penis, and even affects cognition.

During puberty, testosterone levels can spike from less than 0.2 nmol/L to 41 nmol/L in as little as 24 months. 

Total testosterone levels usually peak around age 19 or 20.

Age RangeTotal TestosteroneBioavailable TestosteroneFree Testosterone
12 – 13 Years0.24 – 27.76 nmol/L(7 – 800 ng/dL)N/A<0.01 – 0.44 nmol/L(0.04 – 12.6 ng/dL)
14 Years0.24 – 41.64 nmol/L(7 – 1,200 ng/dL)N/A0.02 – 0.53 nmol/L(0.48 – 15.3 ng/dL)
15 – 16 Years3.47 – 41.64 nmol/L(100 – 1,200 ng/dL)N/A0.06 – 0.68 nmol/L(1.62 – 19.5 ng/dL)
17 – 18 Years10.41 – 41.64 nmol/L(300 – 1,200 ng/dL)N/A0.15 – 0.76 nmol/L(4.28 – 21.8 ng/dL)
19 – 20 Years8.32 – 32.96 nmol/L(240 – 950 ng/dL)N/A0.19 – 0.73 nmol/L(5.36 – 21.2 ng/dL)

3. Normal Testosterone Levels in Young-Adults

Throughout the 20s, total testosterone levels usually remain stable around 10 – 33 nmol/L.

By age 30, total testosterone levels will gradually start to decline in some men at a rate of 1 – 5%. Others won’t start the decline until closer to age 40.

Everything from genetics, dietary status, and drug-use can affect testosterone levels. 

Age RangeTotal TestosteroneBioavailable TestosteroneFree Testosterone
20 to 298.32 – 32.96 nmol/L(240-950 ng/dL)2.88 – 8.92 nmol/L(83.0 – 257.0 ng/dL)0.18 – 0.72 nmol/L(5.05 – 20.7 ng/dL)
30 to 398.32 – 32.96 nmol/L(240-950 ng/dL)2.50 – 8.15 nmol/L(72.0 – 235.0 ng/dL)0.16 – 0.66 nmol/L(4.65 – 19.0 ng/dL)

4. Normal Testosterone Levels in Middle-Aged Men

By age 40, the average total testosterone level of a man is between 13 nmol/L and 30 nmol/L. This is equivalent to around 375 – 916 ng/dL.

The normal testosterone levels for this age-range can vary substantially. The approximate normal range for men between the ages of 40 and 69 is 8 – 33 nmol/L (240 – 950 ng/dL). 

Age RangeTotal TestosteroneBioavailable TestosteroneFree Testosterone
40 to 498.32 – 32.96 nmol/L(240-950 ng/dL)2.12 – 7.39 nmol/L(61.0 – 213.0 ng/dL)0.15 – 0.60 nmol/L(4.26 – 17.10 ng/dL)
50 to 598.32 – 32.96 nmol/L(240-950 ng/dL)1.74 – 6.59 nmol/L(50.0 – 190.0 ng/dL)0.13 – 0.54 nmol/L(3.87 – 15.6 ng/dL)
60 to 698.32 – 32.96 nmol/L(240-950 ng/dL)1.39 – 5.83 nmol/L(40.0 – 168.0 ng/dL)0.12 – 0.48 nmol/L(3.47 – 13.9 ng/dL)

5. Normal Testosterone Levels in the Elderly

By age 70, roughly 25% of men meet laboratory criteria for testosterone deficiencies (less than 10 nmol/L or 300 ng/dL) [6]. 

Around age 60 or 70, men start to experience a much faster rate of testosterone depletion. While total testosterone levels decrease, the amount of SHBG increases at a rate of 1.2% per year. 

This combination can significantly speed up the rate of loss for bioavailable testosterone [4, 5].

The normal bioavailable range of testosterone in older men is still not well established. Research is currently underway to assess what should be considered a normal, healthy range beyond age 70. 

Age RangeTotal TestosteroneBioavailable TestosteroneFree Testosterone
70 to 798.32 – 32.96 nmol/L(240-950 ng/dL)N/A0.11 – 0.42 nmol/L(3.08 – 12.2 ng/dL)
80 to 898.32 – 32.96 nmol/L(240-950 ng/dL)N/A0.09 – 0.36 nmol/L(2.69 – 10.50 ng/dL)
90 to 998.32 – 32.96 nmol/L(240-950 ng/dL)N/A0.08 – 0.30 nmol/L(2.29 – 8.76 ng/dL)

Signs & Symptoms of Testosterone Deficiency in Men

Testosterone plays a role in many aspects of health. It’s involved with immune function, sleep, reproductive health, athletic ability, and anatomy and physiology. 

If testosterone levels are low it can lead to problems affecting many different aspects of health. 

Here are some of the most common signs of testosterone deficiencies in men: 

  • Lowered libido
  • Inability to achieve or maintain an erection
  • Loss of facial or pubic hair
  • Infertility
  • Frequent bone fractures
  • Excessive sweating
  • Loss of height
  • Fatigue
  • Depression or other mood disorders
  • Poor focus and concentration
  • Increased body fat
  • Lowered athletic performance
  • Sleep disturbances

Diagnosing Testosterone Deficiency

The best way to diagnose androgen deficiency is to visit your doctor and get a complete testosterone test. The test involves taking a blood sample and waiting a day or two for the analysis to come back. 

Ask your doctor for a complete testosterone score, including free, total, and bioavailable testosterone. 

If you can’t wait until your visit, doctors often use a quick questionnaire to help identify if testosterone levels are low based on symptoms:  

  1. Do you have a decrease in libido? 
  2. Do you have a lack of energy? 
  3. Do you have a decrease in strength and/or endurance?
  4. Have you lost height? 
  5. Have you noticed a decreased ‘enjoyment of life’? 
  6. Are you sad and/or grumpy? 
  7. Are your erections less strong? 
  8. Have you noted a recent deterioration in your ability to play sports? 
  9. Are you falling asleep after dinner?
  10. Has there been a recent deterioration in your work performance? 

Signs & Symptoms of Testosterone Excess in Men

  • Acne formation
  • Dizziness or Lightheadedness
  • Low Blood Pressure or High Blood Pressure
  • Headaches
  • Nausea
  • Erectile Dysfunction
  • Excessive Hair Growth
  • Anxiety or Depression
  • Chest Pain
  • Shortness of Breath
  • Polycythemia vera
  • Low HDL Cholesterol
  • Prostatitis or BPH
  • Deep Vein Thrombosis

What Are the Normal Testosterone Levels in Females?

Both men and women have testosterone and estrogen. The difference is the ratio between the two hormones. 

In women, total testosterone levels don’t usually exceed 3 nmol/L, while men usually peak around 30 or 40 nmol/L. 

Free testosterone levels are even lower in women because as much as 80% of testosterone in women remains bound to SHBG. Testosterone bound to SHBG will not have any direct impact on the body. Only about 40% of testosterone in men remains bound to SHBG. 

Normal Free & Total Testosterone Levels in Women by Age

The normal testosterone level in women is between 0.5 and 2.4 nmol/L. Anything less than 0.5 is considered deficient, and anything over 2.4 is considered excess. 

However, it’s a little more complicated than this when it comes to assessing testosterone status in women. 

Everybody has a different normal — which can be affected by everything from genetics to exercise status. 

A doctor won’t only look at your testosterone levels to determine if there’s an issue. They need to compare these findings with your estrogen, progesterone, FSH, LH, and thyroid hormone levels as well. 

Testosterone levels can also fluctuate depending on what part of your cycle you’re in. 

Take the figures posted below with a grain of salt. These are meant to serve as a general range for what’s considered normal for most women (but not all). 

Age RangeTotal TestosteroneFree Testosterone
0 – 5 Months0.69 – 2.77 nmol/L(20 – 80 ng/dL)<0.01 nmol/L(0.04 – 0.25 ng/dL)
6 Months – 9 years0.24 – 0.69 nmol/L(7 – 20 ng/dL)<0.01 nmol/L(0.04 – 0.46)
10 – 11 Years0.24 – 1.52 nmol/L(7 – 44 ng/dL)<0.01 – 0.02 nmol/L(0.04 – 0.72 ng/dL)
12 – 16 Years0.24 – 2.60 nmol/L(7 – 75 ng/dL)<0.01 – 0.03 nmol/L(0.04 – 1.06 ng/dL)
17 – 18 Years0.69 – 2.60 nmol/L(20 – 75 ng/dL)<0.01 – 0.03 nmol/L(0.04 – 1.09 ng/dL)
19+ Years0.27 – 2.08 nmol/L(8 – 60 ng/dL)<0.01 – 0.03 nmol/L(0.06 – 1.08 ng/dL)

Bioavailable Testosterone Levels in Women:

We’ve talked a lot about bioavailable testosterone in the section on males. This is a measure of all the testosterone that has a direct biological impact. 

This measurement takes into account both the free testosterone as well as albumin-bound (weakly bound) testosterone. 

In women, only 20% of bound testosterone is bound to albumin (or less), so the numbers are very similar to free testosterone. 

There are also a lot of other complications that can interfere with this number in women, making it less useful for assessing hormonal health than it is for men. 

For example, women taking oral birth control pills (estrogen) can alter the bioavailable testosterone levels:

Oral Estrogen StatusBioavailable Testosterone
Women Taking Oral Estrogen0.03 – 0.14 nmol/L (0.8 – 4.0 ng/dL)
Women Not Taking Oral Estrogen0.03 – 0.35 nmol/L (0.8 – 10.0 ng/dL)

What’s the Role of Testosterone in Women? 

In women, testosterone plays a role in fertility, libido, bone and muscle health, and lactation. It also serves as the precursor to estrogen. 

Some women experience issues converting testosterone into estrogens — leading to a condition called hyperandrogenism. When this happens, testosterone levels become too high, leading to changes in mood, hair growth, fat and muscle deposition, fertility, and libido. 

Signs of Testosterone Deficiency in Women:

  • Lowered libido
  • Depression
  • Fatigue
  • Muscle Weakness
  • Vaginal Dryness
  • Insomnia

Signs of Excess Testosterone in Women:

  • Increased Body Hair (Hirsutism)
  • Increased Muscle Mass
  • Irregular or Skipped Periods
  • Reduced Sex Drive
  • Infertility
  • Irritability, Anxiety, or Depression
  • Reduced Breast Size
  • Excess Weight Gain

Conclusion: What Are Normal Testosterone Levels? 

It’s important to know what type of testosterone you’re looking at before determining whether testosterone levels are too low or too high. 

For men, total testosterone levels usually register somewhere between 10 and 41 nmol/L. Older men may have lower numbers and still be considered normal. Free testosterone is much lower, usually around 0.3 to 1 nmol/L. 

Arguably, the most important measurement of testosterone in men is the bioavailable testosterone — which should remain somewhere between 3 and 8 nmol/L. 

In women, testosterone levels can vary depending on the time of the month but usually remains within 0.5 and 2.4 nmol/L. 

If you think you’re experiencing side effects from having either too much or too little testosterone, it’s important to visit your doctor for a proper assessment and some blood tests. 

References Cited in this Article

  1. Fabbri, E., An, Y., Gonzalez-Freire, M., Zoli, M., Maggio, M., Studenski, S. A., … & Ferrucci, L. (2016). Bioavailable testosterone linearly declines over a wide age spectrum in men and women from the Baltimore Longitudinal Study of Aging. Journals of Gerontology Series A: Biomedical Sciences and Medical Sciences, 71(9), 1202-1209.
  2. Yeap, B. B., Araujo, A. B., & Wittert, G. A. (2012). Do low testosterone levels contribute to ill-health during male aging?. Critical reviews in clinical laboratory sciences, 49(5-6), 168-182.
  3. Wheeler, M. J. (1995). The determination of bio-available testosterone. Annals of clinical biochemistry, 32(4), 345-357.
  4. Horstman, A. M., Dillon, E. L., Urban, R. J., & Sheffield-Moore, M. (2012). The role of androgens and estrogens on healthy aging and longevity. Journals of Gerontology Series A: Biomedical Sciences and Medical Sciences, 67(11), 1140-1152.
  5. Lapauw, B., Goemaere, S., Zmierczak, H., Van Pottelbergh, I., Mahmoud, A., Taes, Y., … & Kaufman, J. M. (2008). The decline of serum testosterone levels in community-dwelling men over 70 years of age: descriptive data and predictors of longitudinal changes. European Journal of Endocrinology, 159(4), 459.
  6. Clapauch, R., Braga, D. J. D. C., Marinheiro, L. P., Buksman, S., & Schrank, Y. (2008). Risk of late-onset hypogonadism (andropause) in Brazilian men over 50 years of age with osteoporosis: usefulness of screening questionnaires. Arquivos Brasileiros de Endocrinologia & Metabologia, 52(9), 1439-1447.

Posted

in

by

Tags:

Comments

Leave a Reply

Your email address will not be published. Required fields are marked *