Testosterone unit converter: nmol/L to ng/dL

Australian and New Zealand labs report total testosterone in nmol/L^1,2. Most US lab results are given as a weight per volume instead³, so a US article might quote the same result in ng/dL. A result of 15 nmol/L, for example, is about 433 ng/dL. Type your number into the converter below and pick the unit it's in. The maths happens in your browser, and the converter doesn't save what you type or send it anywhere. It changes units only. It won't tell you whether a result is good or bad.

How do you convert testosterone from nmol/L to ng/dL?

Multiply nmol/L by 28.84 to get ng/dL. To go the other way, divide ng/dL by 28.84, which is the same as multiplying by 0.0347.

The factor comes from the weight of the testosterone molecule. Its molar mass is about 288.4 g/mol⁴, so one nanomole weighs about 288.4 nanograms^3,4. A litre is ten decilitres, which turns 288.4 ng per litre into 28.84 ng per decilitre.

• nmol/L to ng/dL: nmol/L × 28.84
• ng/dL to nmol/L: ng/dL ÷ 28.84
• nmol/L to ng/mL: nmol/L × 0.2884 (1 ng/mL is 100 ng/dL)

If a source rounds the factor to 28.8, the answer moves by less than 0.2%. For scale, the Waikato lab states a measurement uncertainty of 10% for its own testosterone test², so the rounding difference is tiny by comparison.

What do common testosterone numbers convert to?

Rounded values. The first table starts from nmol/L, the unit on an Australian or NZ report. The second starts from round ng/dL figures, for when you're reading US material.

nmol/L (AU/NZ reports)	ng/dL (US)	ng/mL
6	173	1.7
8	231	2.3
10	288	2.9
12	346	3.5
15	433	4.3
20	577	5.8
25	721	7.2
30	865	8.7

nmol/L	ng/dL (as quoted in US content)
6.9	200
10.4	300
13.9	400
17.3	500
20.8	600
27.7	800
34.7	1,000

These are unit conversions only. They don't say whether a figure is normal for you.

How do you read testosterone units on an Australian or NZ lab report?

Each line shows your result, the unit and the lab's reference interval (sometimes called the normal range). SA Pathology in South Australia lists 8 to 30 nmol/L for males 16 and over¹, and Health New Zealand's Waikato laboratory lists 9 to 30 nmol/L for adult men². Ranges can differ with the testing method, which is why Pathology Tests Explained says to check your result against the range printed by the lab that did your test⁵. bpac nz makes the same point for immunoassays⁶.

• Total testosterone: nmol/L.
• SHBG (sex hormone binding globulin): also nmol/L, with a range of 10 to 45 for males 18 and over at SA Pathology¹. Don't run it through 28.84. That factor only works for testosterone.
• Free testosterone: a much smaller number, so watch the decimal point. SA Pathology prints a provisional range of 0.20 to 0.60 nmol/L for males 18 and over¹, while bpac nz gives free testosterone in both nmol/L and pmol/L⁶. One nmol/L is 1,000 pmol/L, so 0.25 nmol/L is the same as 250 pmol/L. If a source gives free testosterone in pg/mL, multiply by 3.467 to get pmol/L (that's 1,000 divided by the molar mass⁴).

What comes back also depends on what was requested. At Awanui Labs in New Zealand, since 17 September 2024 a "Testosterone only" request reports total testosterone with no SHBG or calculations, while "Testosterone + SHBG" adds SHBG and a calculated free testosterone⁷. The blood test checklist covers what to ask for, and the free testosterone and SHBG guide explains how the markers fit together.

Why do US articles use ng/dL?

Because most US lab results are reported in what are called conventional units, a weight per volume such as nanograms per decilitre, while most other countries use SI units, which measure amounts in moles per litre³. MedlinePlus, run by the US National Library of Medicine, gives 8.6 to 29.0 nmol/L for men aged 17 to 50, but it prints the ng/dL version first: 249 to 836 ng/dL⁸. A study that harmonised results from US and European men put the range for healthy, non-obese men aged 19 to 39 at roughly 9.2 to 31.8 nmol/L, published as 264 to 916 ng/dL⁹. The Endocrine Society of Australia's position statement works in nmol/L¹⁰.

Two traps follow. One is comparing a US figure with your report without converting it. The other is treating a converted US range as your lab's range. The two sources above give different ranges, partly because they describe different groups of men, and the harmonisation study found that a substantial share of the variation between groups came down to lab methods⁹.

Does one testosterone number tell you if it's low?

No. A single result, in any unit, is something to talk through with your GP, not a verdict. Here's why:

• Timing matters. Levels are highest in the morning and fall during the day⁵. bpac nz advises a test between 7 am and 11 am, ideally after an overnight fast⁶. Healthify NZ says before 9 am¹¹, and the Endocrine Society of Australia says 8 to 10 am, adjusted for shift workers¹⁰.
• Short-term things move it. Acute illness, recent food (carbohydrates) or alcohol can cause a temporary drop⁶.
• Repeat tests often differ. Up to 30% of men with one isolated low result have a normal level when retested¹⁰, which is why guidance calls for at least two morning measurements^6,10,12.
• Methods vary. Healthy Male says accurate testosterone measurement needs mass spectrometry, that immunoassay values are less accurate, and that ranges vary between labs and methods¹². Awanui Labs says the immunoassay it now uses performs comparably to mass spectrometry in men⁷. The Waikato lab states a measurement uncertainty of 10% for its test².
• A flag isn't a diagnosis. A result outside the range doesn't always mean there's a health problem, and your doctor reads it alongside your history and symptoms^5,6,13.

For how results spread across age groups, see testosterone levels by age. If you'd like someone to go through your whole panel in plain English, marker by marker, that's what a Teak coach does. Teak is coaching, not medical care. We don't diagnose or treat, and if anything looks medical we'll tell you plainly to take it to your GP straight away (see safety). Chatting first costs nothing. See how it works.

This converter and page are general information, not medical advice. How we research and check pages like this is set out in our editorial policy.