Osmolality Calculator

Calculate serum osmolality. Calculated and measured.

Lab Chemistry

Sodium

mEq/L

Glucose

mg/dL

Bun

mg/dL

Measured

mOsm/kg

Osmolality

Calculated290.9mOsm/kgExpected

StatusPhysiological Balance

Physiological Balance

Metabolic Assessment

Clinical Reference

Normal Serum Osm.275 - 295

Normal Osm. Gap< 10

Disclaimer: This tool is for informational purposes only and is not a substitute for professional medical advice.

About this calculator

Overview

Calculated osmolality = 2×Na + Glucose/18 + BUN/2.8. Normal 275–295. Osmolar gap = Measured − Calculated. High gap: toxins.

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Pro Tips

Fun Facts

Formula: Osm = 2×Na + Glu/18 + BUN/2.8. Gap = Measured − Calc.