Serum Osmolality Calculator Formula:

   Osm = 2 * Na + BUN / 2.8 + glucose / 18 + EtOH/4.6

Where:

   Na: Blood Sodium Level, mEq/L
   BUN: Blood Urea Nitrogen Level, in mg/dL
   glucose: Bood Glucose Level, in mg/dL
   EtOH: Bood Ethanol Level, in mg/dL

Normal serum osmolality is 285-295 mOsm/kg