Corrected sodium calculator for hyperglycemia

How to use it

1. Enter the measured sodium in mmol/L (mEq/L).
2. Pick the glucose units and enter the blood glucose.
3. Read the corrected sodium by Katz and by Hillier.

The formulas

With glucose in mg/dL:

• Katz: corrected Na = Na + 1.6 × (glucose − 100) / 100
• Hillier: corrected Na = Na + 2.4 × (glucose − 100) / 100

Glucose in mmol/L is multiplied by 18.016 to get mg/dL first.

Worked example

Sodium 130 mmol/L, glucose 400 mg/dL (22.2 mmol/L). Excess glucose 300 mg/dL, that is 3 × 100:

• Katz: 130 + 1.6 × 3 = 134.8 mmol/L
• Hillier: 130 + 2.4 × 3 = 137.2 mmol/L

A sodium that looked low is in or near the normal range once glucose is taken into account.

Tips

• Use sodium and glucose from the same blood sample.
• A high corrected sodium during treatment of diabetic ketoacidosis or a hyperosmolar state means water loss that needs attention.
• This is an estimate for information, not a diagnosis or a treatment decision.