Corrected sodium calculator (hyperglycemia)
High glucose dilutes blood sodium; this tool estimates what the sodium would be at a normal glucose.
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How to use it
- Enter measured sodium, blood glucose and glucose unit.
- The result appears straight away and updates as you edit.
- Copy the result, or copy a link that keeps the same values to share it.
How it is calculated
Katz: Na + 1.6 × (glucose - 100) ÷ 100. Hillier: Na + 2.4 × (glucose - 100) ÷ 100, with glucose in mg/dL (mmol/L × 18.0156). At 100 mg/dL or less there is no correction.
Example
Inputs: Measured sodium = 130 mmol/L, Blood glucose = 400, Glucose unit = mg/dL. Result: Corrected sodium (Katz): 134.8 mmol/L; Corrected sodium (Hillier): 137.2 mmol/L.
Limits and caveats
- Both factors come from small studies, and the true shift varies between patients.
- The result does not set how fast to correct sodium or which fluids to give.
- An educational estimate that does not replace assessment by a doctor or pharmacist.
Questions about this tool
Why does sodium fall when glucose rises?
High glucose draws water out of cells into the blood and dilutes sodium, without a true sodium loss.
Which one should I use, Katz or Hillier?
The Katz factor (1.6) is older; Hillier found in 1999 that 2.4 fits better at very high glucose, so both are shown.
Should I correct at a normal glucose?
No. The correction is for hyperglycemia, and the tool returns the measured value at 100 mg/dL or less.