Not for clinical use. This calculator supports clinical decisions (dosing, a risk score, an obstetric or laboratory assessment) and has not been reviewed by a named qualified clinician. It is published for reference and education only, it is excluded from search indexing for that reason, and it must not be used to guide the care of any patient. Verify every figure against the primary source and your own professional judgement.
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.
This content is provided for educational purposes only and has not been reviewed by a qualified specialist in this field. See our methodology and review panel.