How to Convert ng/dL to nmol/L
ng/dL is a mass concentration, while nmol/L is a molar concentration. To convert between them, the calculator uses the molecular weight of the selected molecule. This is why testosterone, estradiol, progesterone, cortisol, and aldosterone each have a different conversion factor.
nmol/L = (ng/dL x 10) / molecular weight ng/dL = (nmol/L x molecular weight) / 10 Testosterone ng/dL to nmol/L
Testosterone is the most common reason people need this conversion. In many US lab reports, total testosterone is shown in ng/dL. In many international references, testosterone is shown in nmol/L.
Using testosterone's molecular weight of 288.42 g/mol, the conversion factor is about 0.0347. That means 300 ng/dL testosterone equals about 10.40 nmol/L, and 500 ng/dL equals about 17.34 nmol/L. For total testosterone with male and female reference ranges and the total-vs-free distinction, use the dedicated testosterone conversion calculator.
Supported Molecules and Conversion Factors
Select the exact molecule before converting. The same ng/dL value can produce a different nmol/L result when molecular weight changes.
| Molecule | Molecular weight | 1 ng/dL equals | Common use |
|---|---|---|---|
| Testosterone | 288.42 g/mol | 0.0347 nmol/L | Total testosterone and androgen assessment |
| Estradiol (E2) | 272.38 g/mol | 0.0367 nmol/L | Estrogen and reproductive hormone testing |
| Progesterone | 314.46 g/mol | 0.0318 nmol/L | Ovulation, luteal phase, and pregnancy-related testing |
| Cortisol | 362.46 g/mol | 0.0276 nmol/L | Adrenal hormone assessment when reported in ng/dL |
| Aldosterone | 360.44 g/mol | 0.0277 nmol/L | Adrenal and blood pressure-related testing |
| Androstenedione | 286.41 g/mol | 0.0349 nmol/L | Adrenal and gonadal androgen evaluation |
Common Conversion Examples
These quick examples show typical hormone conversions and why the molecule selection matters.
| Molecule | ng/dL | nmol/L | Context |
|---|---|---|---|
| Testosterone | 300 ng/dL | 10.40 nmol/L | Common testosterone comparison |
| Testosterone | 500 ng/dL | 17.34 nmol/L | Mid-range testosterone example |
| Testosterone | 800 ng/dL | 27.74 nmol/L | Higher testosterone example |
| Estradiol | 10 ng/dL | 0.37 nmol/L | Same molecule, different factor |
| Progesterone | 100 ng/dL | 3.18 nmol/L | Steroid hormone example |
| Aldosterone | 10 ng/dL | 0.28 nmol/L | Adrenal hormone example |
ng/dL vs nmol/L
These units express the same concentration in different ways. ng/dL tells you how much mass is present in one deciliter. nmol/L tells you how many molecules are present in one liter.
Neither unit is inherently more accurate. The important step is matching the unit on your lab report to the unit used by the reference range or guideline you are comparing against.
Frequently Asked Questions
What is the testosterone conversion factor from ng/dL to nmol/L?
For testosterone, multiply ng/dL by about 0.0347 to get nmol/L. The reverse conversion is nmol/L divided by 0.0347.
What is 300 ng/dL testosterone in nmol/L?
300 ng/dL testosterone equals approximately 10.40 nmol/L using a molecular weight of 288.42 g/mol.
Is the ng/dL to nmol/L conversion the same for every hormone?
No. The formula is the same, but the conversion factor changes because every hormone has its own molecular weight.
Can I use this calculator for free testosterone?
This page can convert any testosterone value expressed in ng/dL, but free testosterone is often reported in pg/mL, pmol/L, or ng/dL depending on the lab. If you need calculated free testosterone from total testosterone, SHBG, and albumin, use the Free Testosterone Calculator.
Can this replace medical interpretation?
No. Unit conversion only changes the measurement format. Diagnosis and treatment decisions require clinical context and a qualified healthcare professional.
Conclusion
The ng/dL to nmol/L conversion is straightforward once the molecule is selected. Testosterone uses a factor of about 0.0347, while other hormones use their own molecular-weight-based factors.
Use this calculator to compare hormone reports, review international reference ranges, or check the reverse conversion quickly. Always pair the converted number with the clinical context and the reference range from your own laboratory.