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Androstenedione in two units: the short answer
To convert androstenedione from ng/dL to nmol/L, multiply by 0.0349. To go back from nmol/L to ng/dL, multiply by 28.65 (or divide by 0.0349). For example, 150 ng/dL × 0.0349 = 5.24 nmol/L. The converter above works in both directions and shows where the result sits against typical reference ranges.
What the test measures
Androstenedione is an androgen made by the adrenal glands and ovaries or testes. US labs report it in ng/dL; SI labs in nmol/L. Molar mass is 286.4 g/mol, so 1 ng/dL = 0.0349 nmol/L and 1 nmol/L = 28.6 ng/dL.
Why the units differ
Androstenedione is used in PCOS work-ups, CAH monitoring and when an androgen-secreting tumour is suspected. Reports from different countries need converting to compare.
Where the factor comes from
The conversion factor comes from the molar mass (286.41 g/mol) and the volume units on each side. Laboratories may round the factor slightly differently, which can change the last digit but never the clinical meaning.
How to convert step by step
- Check the unit printed next to the result on your report – ng/dL or nmol/L.
- ng/dL → nmol/L: multiply by 0.0349.
- nmol/L → ng/dL: multiply by 28.65.
- Round to the same number of decimals your lab uses.
Worked example in reverse: 1.75 nmol/L × 28.65 = 50.1 ng/dL.
Androstenedione conversion chart
| ng/dL | nmol/L |
|---|---|
| 20 | 0.7 |
| 30 | 1.05 |
| 50 | 1.75 |
| 75 | 2.62 |
| 100 | 3.49 |
| 150 | 5.24 |
| 200 | 6.98 |
| 250 | 8.73 |
| 300 | 10.47 |
| 500 | 17.45 |
| nmol/L | ng/dL |
|---|---|
| 0.7 | 20.1 |
| 1.05 | 30.1 |
| 1.75 | 50.1 |
| 2.62 | 75.1 |
| 3.49 | 100 |
| 5.24 | 150.1 |
| 6.98 | 200 |
| 8.73 | 250.1 |
| 10.47 | 300 |
| 17.45 | 500 |
Androstenedione levels: what the numbers mean
| Category | ng/dL | nmol/L |
|---|---|---|
| Typical adult women (premenopausal)Varies widely by lab, age and cycle phase | 30 – 200 | 1.05 – 6.98 |
| Typical adult menLab dependent | 40 – 150 | 1.4 – 5.24 |
Approximate adult ranges; LC-MS/MS assays give lower values than older immunoassays. Use the range printed on your report.
Approximate adult ranges; LC-MS/MS assays give lower values than older immunoassays. Use the range printed on your report.
Interpreting androstenedione results
Raised androstenedione can be seen in polycystic ovary syndrome, congenital adrenal hyperplasia and, rarely, androgen-secreting tumours of the adrenal or ovary. In CAH treatment it is one of the markers used to judge whether the steroid dose is right. Very high androgen levels with rapid onset of symptoms such as voice deepening need prompt specialist review.
A single result outside the reference range is common and often not significant on its own. Reference ranges are set so that about 1 in 20 healthy people fall outside them, and every laboratory sets its own limits for its method. Use the range printed on your report and discuss results with the clinician who ordered the test.
When to see a doctor
Contact your clinician if a result is flagged as abnormal and you have symptoms, if a value is far outside the range, or if results are changing over time. This page explains units; it cannot diagnose or replace medical advice.
Frequently asked questions
What is 5 nmol/L androstenedione in ng/dL?
5 × 28.6 = 143 ng/dL.
Is androstenedione the same as testosterone?
No. It is a precursor that can be converted to testosterone or estrone. It has its own conversion factor.
Can I use this converter for any lab?
Yes for the unit conversion, which is fixed by chemistry. Reference ranges differ between labs and methods, so compare your converted value with your own lab's range.