Corrected Sodium for Hyperglycemia Calculator
In hyperglycemia, high blood glucose pulls water out of cells into the bloodstream, diluting the measured serum sodium and producing a falsely low value. Correcting the sodium estimates what the concentration would be at a normal glucose, helping distinguish dilutional pseudohyponatremia from true sodium depletion. This calculator applies either the Katz factor (1.6 mEq/L per 100 mg/dL glucose above 100) or the Hillier factor (2.4), letting you compare both. Enter measured sodium in mEq/L and glucose in mg/dL. This is an educational estimate, not medical advice.
Corrected sodium formula
Adjustment = factor * (glucose - 100) / 100
Corrected Na = measured Na + adjustment
Katz factor = 1.6; Hillier factor = 2.4
Na in mEq/L; glucose in mg/dL
If glucose is at or below 100 mg/dL, no correction is applied and corrected sodium equals measured sodium. The Hillier factor is often preferred at very high glucose levels.
Clinical context
- The dilutional effect is most relevant in diabetic ketoacidosis and hyperosmolar hyperglycemic state.
- A normal or high corrected sodium with a low measured sodium points to dilution, not sodium loss.
- Reference sodium range is roughly 135 to 145 mEq/L in most labs.
- Glucose in mmol/L must be multiplied by 18 to convert to mg/dL before entry.
- Correction is a guide; fluid and electrolyte decisions rest with the clinician.
Corrected sodium: frequently asked questions
Why does sodium need correcting in hyperglycemia?
High blood glucose draws water from cells into the blood, diluting the measured sodium concentration. This dilutional effect produces a falsely low (pseudohyponatremia) reading. Correcting estimates what the sodium would be at a normal glucose, revealing the true sodium status.
What is the difference between the Katz and Hillier factors?
Katz (1973) adds 1.6 mEq/L of sodium for every 100 mg/dL of glucose above 100. Hillier (1999) uses 2.4, derived experimentally and often preferred when glucose exceeds about 400 mg/dL. This calculator lets you choose the correction factor.
What units does this use?
Measured sodium is entered in mEq/L (equivalent to mmol/L) and glucose in mg/dL. If your glucose is in mmol/L, multiply by 18 to convert to mg/dL before entering.
Does correction change management?
It can. A corrected sodium that is normal or high alongside a low measured sodium indicates dilutional pseudohyponatremia rather than true sodium loss, which affects fluid choices. Interpretation belongs with the treating clinician.
Is this a diagnostic tool?
No. This is an educational calculator. Sodium correction is one data point in managing hyperglycemic emergencies and must be interpreted with the full clinical picture by a qualified clinician.
Official sources
- National Library of Medicine (NCBI): Hyponatremia and sodium correction literature.
- National Institute of Diabetes and Digestive and Kidney Diseases: Diabetic emergencies and electrolytes.
Reviewed by the CalculatorHub team, edited by James Graham, 17 June 2026. See our methodology.