Testosterone Levels by Age Calculator

For healthy, non-obese men aged 19 to 39, total testosterone runs from 264 to 916 ng/dL.¹ Every lab we order at Opt Health is read by a physician before anyone is offered a treatment.

Older men have their own published ranges, and this testosterone levels by age calculator matches your age to the right one. Enter one lab result to see where it sits against that range and against the cutoff used by the American Urological Association (AUA).²

Where the Testosterone Levels by Age Ranges Come From

The testosterone levels by age calculator draws on three population studies, and each one covers a different stretch of adult life. The three studies span men from 19 to 79, and a fourth study describes testosterone after 80.

The Harmonized Range for Men 19 to 39

The harmonized range comes from four cohort studies of 9,054 community-dwelling men in the United States and Europe. It uses the healthy non-obese men aged 19 to 39.¹ Researchers cross-calibrated each cohort's testosterone assay to the reference method at the Centers for Disease Control and Prevention (CDC). That step lets a result from one laboratory line up with results from another.¹

The published range describes healthy, non-obese men. In the same study, age-specific levels in non-obese men ran higher than in all men combined.¹

The Middle Third for Men 20 to 44

For men 20 to 44, a 2022 study split national survey data into 5-year bands and found that the middle third of results sits lower after age 29.³ The data came from 1,486 men in the National Health and Nutrition Examination Survey (NHANES) between 2011 and 2016. Men taking hormonal medication and men tested in the afternoon or evening were left out.³

The 2022 study used the AUA definition of a normal level, which is the middle third of the range. The authors then used the bottom of each band as an age-specific cutoff for low testosterone.³

Every proposed cutoff sits above 300 ng/dL.³ A younger man can clear the AUA figure and fall under the middle third for his age. A physician uses that gap to decide whether a result needs a second look.

Decade Ranges for Men 40 to 79

For men 40 to 79, the Massachusetts Male Aging Study published a range for each decade in men it classed as apparently healthy.⁴ That label meant no reported chronic disease, no hormone-altering prescriptions, a body mass index of 29 or less, six or fewer drinks a day, and no smoking.⁴

Chronic disease and a high body mass index both lowered testosterone in this cohort.⁴ Its samples were nonfasting and taken within 4 hours of waking.⁴ The Endocrine Society guideline asks for a fasting morning draw, and that is the result to enter in the calculator.⁶

Testosterone in Men 80 and Older

Testosterone declines gradually from age 35 and more steeply after 80, according to 10,904 samples measured by mass spectrometry in one Australian laboratory.⁵ The ranges in this calculator stop at 79, so for men 80 and older the calculator shows the AUA comparison and the result in both units. A physician then reads the number against symptoms and a repeat morning draw.²

What the AUA 300 ng/dL Cutoff Means

The AUA guideline names a total testosterone below 300 ng/dL as a reasonable cutoff in support of a low testosterone diagnosis.² The AUA grades that statement a Moderate Recommendation based on Grade B evidence.²

The guideline makes a stronger call about timing. A diagnosis should follow two early-morning measurements taken on separate occasions, which it grades a Strong Recommendation based on Grade A evidence.² The calculator above puts the single cutoff beside an age-matched range, so a physician starts with two reference points for one result.

Three Results Read by Age

Three lab results read differently at ages 28, 42, and 66. The table runs each one through the calculator.

The 28-year-old clears the AUA cutoff and sits below the middle third for men his age. The 66-year-old falls under the AUA cutoff and sits inside the published range for his decade.^2,3,4 For both men, the next step is a second early-morning draw and a physician who reads the pair against their symptoms.^2,6

What Moves a Testosterone Result Besides Age

Body weight, chronic illness, and the timing of the blood draw all shift a testosterone result alongside age. Tell your physician which of these apply to you, so your number is read against the right table.

• Body weight. Higher weight and body mass index were linked with lower testosterone in 10,904 Australian samples, and so was shorter stature.⁵
• Chronic disease. Men with a reported chronic condition had lower levels than apparently healthy men in the Massachusetts Male Aging Study.⁴
• Smoking. Smoking tended to raise total testosterone in the same cohort.⁴ A physician reads a smoker's result with that in mind.
• Time of the draw. The 2022 NHANES analysis left out afternoon and evening samples, and both guidelines ask for an early-morning draw.^2,3,6
• The laboratory assay. Cross-calibrating four cohorts to the CDC reference method reduced the gap between results for men of similar ages.¹

These factors explain why two men with the same result can need different next steps. A physician weighs these factors with your symptoms before offering any treatment.

How to Get a Testosterone Result You Can Compare

The Endocrine Society recommends a fasting, early-morning draw on an accurate and reliable assay as the first diagnostic test.⁶ Four steps follow the guideline advice on testing.

• Book the blood draw early in the morning, fasting, as the Endocrine Society guideline recommends.⁶
• Repeat the test on a separate occasion before treating a low number as a diagnosis.²
• Ask about free testosterone when your total sits near the lower limit or you have a condition that changes sex hormone-binding globulin (SHBG). The Endocrine Society recommends measuring it by equilibrium dialysis or estimating it with an accurate formula.⁶
• Read the unit on your report. The Massachusetts Male Aging Study pairs 8.7 nmol/L with 251 ng/dL, so multiply nmol/L by about 28.84 to get ng/dL.⁴

Our guide to testosterone levels through the years explains how free testosterone differs from total testosterone.

Reading Your Testosterone Level with a Physician

A testosterone number becomes a plan once a physician reads it against your symptoms, a repeat draw, and the rest of your labs. The Endocrine Society recommends diagnosing low testosterone only in men who have symptoms and signs of deficiency along with consistently low levels.⁶

The pattern we see most often is a single out-of-range value with no trend behind it. A second morning result shows whether that value repeats, and a normal repeat or an absence of symptoms changes the reading.^2,6

Our pages on low testosterone symptoms in men and the signs that you need a testosterone test help you prepare for that conversation.

The NHANES and Massachusetts Male Aging Study ranges describe men who were not taking hormone-altering medication.^3,4 If you already take testosterone, your prescriber reads your level against your treatment plan. Women's hormone results are read on our women's track, which starts with the same 55+ biomarker panel.

The Opt Take on Testosterone Levels by Age

An age-matched range tells you where one number sits. At Opt Health, that number starts a plan. Your first panel covers 55+ biomarkers, drawn at home or at a partner lab, and an Opt Health physician reviews the results with you 1:1.

Labs and a physician consultation repeat every 3 to 4 months, and your plan is adjusted on what the numbers did. That schedule builds the series of results a single draw cannot give you. When treatment fits, prescriptions, peptides and supplements ship from our pharmacy to your door.

Get started: Begin with Opt Health, where a physician reads your labs, builds your plan, and adjusts it over the loop.

Frequently Asked Questions

This calculator compares one lab value with published population data for general education. It does not diagnose low testosterone or replace an evaluation by a physician.