How do I convert Phenytoin from mg/L to µmol/L?

µmol/L = mg/L × 3.964. For example, 15 mg/L equals 59.5 µmol/L.

How many µmol/L are 15 mg/L?

15 mg/L equal 59.5 µmol/L (Phenytoin).

Drugs & toxicology

µmol/L = mg/L × 3.964

Enter a value in any unit and all other units fill in.

mg/L µmol/L

mg/L → µmol/L	µmol/L = mg/L × 3.964
µmol/L → mg/L	mg/L = µmol/L × 0.2523

Highlighted: values inside the adult reference range.

10 – 20 mg/L = 39.64 – 79.28 µmol/L

Source: FDA drug label (DailyMed): phenytoin · Last reviewed: 2026-10-14