Clinical Calculator

HHS Calculator

Corrected Sodium & Serum Osmolality for Hyperosmolar Hyperglycemic State

Enter Lab Values

Sodium (mEq/L)

Glucose (mg/dL)

Potassium (mEq/L)

BUN (mg/dL)

Enter all four values above to see results.

Corrected Sodium

Corrected Na = Measured Na + ((Glucose − 100) / 100) × factor
factor = 1.6 if glucose ≤ 400 mg/dL
factor = 2.4 if glucose > 400 mg/dL

Effective Osmolality

Osmolality = 2 × (Corrected Na + K) + (Glucose / 18) + (BUN / 2.8)

Clinical Thresholds

≤ 310 mmol/L — Normal osmolality

311–320 mmol/L — Hyperosmolar

> 320 mmol/L — Consistent with HHS

This calculator is intended for educational and clinical reference purposes. Always correlate with full clinical assessment.