Convert pg/mL to nmol/L (and back)
How to convert a value from your report into other units — with the formula and examples.
Formula: nmol/L = pg/mL ÷ M; pmol/L = pg/mL × 1000 ÷ M (M is the molar mass, g/mol; 1 pg/mL = 1 ng/L).
How it works
Picograms per milliliter are typical for thyroid hormones and sex steroids. The conversion goes through the molar mass; the factors for T4, T3, cortisol and estradiol are below.
Examples for common markers
| Marker | Molar mass / valence | Conversion example |
|---|---|---|
| Free T4 | 776,9 | 1.0 pg/mL = 1.29 pmol/L |
| Free T3 | 650,9 | 3.1 pg/mL = 4.8 pmol/L |
| Cortisol | 362,5 | 10 pg/mL = 27.6 pmol/L |
| Estradiol | 272,4 | 27.2 pg/mL = 100 pmol/L |
Check the units on your report: for hormones, pg/mL and ng/dL differ by a factor of 10 (1 ng/dL = 10 pg/mL).