21 nmol/L to ng/mL Converter
Convert any lab value from nmol/L to ng/mL (or back) for 16 hormones and vitamins - pick the molecule below and this calculator uses its exact molecular weight. Also written "nM" or "nmol/l" on some lab reports - 21 nM and 21 nmol/L mean exactly the same thing.
Common nmol/L Values
Same value, converted for every molecule
| Molecule | MW (g/mol) | 21 nmol/L in ng/mL |
|---|---|---|
| Vitamin D (25-Hydroxyvitamin D) | 400.64 | 8.41344 ng/mL |
| Testosterone | 288.42 | 6.05682 ng/mL |
| Estradiol (E2) | 272.38 | 5.71998 ng/mL |
| Cortisol | 362.46 | 7.61166 ng/mL |
| Progesterone | 314.47 | 6.60387 ng/mL |
| Vitamin A (Retinol) | 286.45 | 6.01545 ng/mL |
| Vitamin E (Alpha-Tocopherol) | 430.71 | 9.04491 ng/mL |
| Aldosterone | 360.45 | 7.56945 ng/mL |
| Dehydroepiandrosterone (DHEA) | 288.42 | 6.05682 ng/mL |
| DHEA-Sulfate (DHEA-S) | 368.49 | 7.73829 ng/mL |
| Vitamin B12 (Cobalamin) | 1355.4 | 28.4634 ng/mL |
| Folate (Folic Acid) | 441.4 | 9.2694 ng/mL |
| Melatonin | 232.28 | 4.87788 ng/mL |
| Thyroxine (T4) | 776.87 | 16.31427 ng/mL |
| Triiodothyronine (T3) | 651.01 | 13.67121 ng/mL |
| Androstenedione | 286.41 | 6.01461 ng/mL |
Each row uses the same value entered above, converted with that molecule's own molecular weight. Custom molecular weight isn't included here since it has no fixed value of its own.
Converting Vitamin D from nmol/L to ng/mL isn’t complicated once you know the molecular weight involved. Here’s the full walkthrough for 21 nmol/L.
Step 1: Multiply 21 nmol/L by the molecular weight of Vitamin D, 400.64 g/mol: 21 × 400.64 = 8413.44.
Step 2: Divide that result by 1000 to convert nanomoles to nanograms: 8413.44 ÷ 1000 = 8.41344.
That gives a final answer of 8.41344 ng/mL for 21 nmol/L – the calculator above does this instantly for any other number.
