Phenytoin unit converter
Convert phenytoin between mcg/mL and µmol/L. Type in either box. The factors come from our catalog and are checked by code.
AI-verified against cited sources. Awaiting expert reviewLast reviewed 2026-10-03
1 mcg/mL = 3.964 µmol/L. Nothing you type here leaves your browser.
The conversion
- 1 mcg/mL = 3.964 µmol/LFrom mcg/mL to µmol/L: multiply by 3.964. Back again: divide by 3.964.
mcg/mL and mg/L give the same number.
Mass and molar units are linked by the molecular weight: 252.27 g/mol (phenytoin (free acid), C15H12N2O2). Source: PubChem, National Library of Medicine.
Common values
From zero to about twice the usual upper limit, plus the usual limits themselves.
| mcg/mLsame as mg/L | µmol/L |
|---|---|
| 5 | 20 |
| 10 | 40 |
| 15 | 59 |
| 20 | 79 |
| 25 | 99 |
| 30 | 119 |
| 35 | 139 |
| 40 | 159 |
Usual ranges in each unit
What labs print as the reference range, by who was tested. Sources for each range are on the Phenytoin page.
| Who | mcg/mL | µmol/L |
|---|---|---|
| Adults | 10–20 | 40–79 |