Serum Osmolality Calculator Serum Sodium (mEq/L) Serum Glucose (mg/dL) Serum Urea/BUN (mg/dL) Calculate Osmolality Result Calculated Serum Osmolality: 0 mOsm/kg Formula used: Osmolality = (Na × 2) + (Glucose ÷ 18) + (BUN ÷ 2.8) Facebook Twitter Youtube