Convert mcg/L to µmol/L (and back)
How to convert a value from your report into other units — with the formula and examples.
mcg/L=µmol/L
µmol/L = mcg/L ÷ M; nmol/L = mcg/L ÷ M × 1000 (M is the substance's molar mass, g/mol)
How it works
Micrograms per liter express the mass of a substance, micromoles per liter the number of molecules. There is no single factor between them: the conversion depends on the molar mass of the particular substance. The number in µmol/L is always M times smaller than in mcg/L (M is the molar mass).
Examples for common markers
| Marker | Molar mass / valence | Conversion example |
|---|---|---|
| Cortisol | 362,5 | 27.6 mcg/L = 76 nmol/L |
| Testosterone | 288,4 | 288 mcg/L = 1000 nmol/L |
| Progesterone | 314,5 | 31.5 mcg/L = 100 nmol/L |
| Estradiol | 272,4 | 0.1 mcg/L (100 pg/mL) = 367 pmol/L |
| Vitamin B12 | 1355 | 135 pg/mL = 100 pmol/L |
A practical rule: mcg/L ÷ M = µmol/L; µmol/L × M = mcg/L; for nmol/L, multiply the result by 1000. Check the exact factor for your marker.