Corrected Sodium for Glucose Calculator

How it is calculated

The tool adds a fixed correction to the measured sodium: correction = 1.6 × (glucose − 100) ÷ 100 and corrected Na = measured Na + correction. Sodium is in mEq/L (the same number as mmol/L) and glucose is in mg/dL. The reference point is 100 mg/dL, and the factor is always 1.6 per 100 mg/dL; the tool does not switch to another factor at very high glucose.

Both values must be above zero. The corrected sodium and the correction are rounded to one decimal, and the correction is shown with a plus sign when it is zero or positive. If glucose is below 100 mg/dL the correction is negative, so the corrected value comes out slightly lower than the measured one. This is an estimate for interpreting a lab result, not medical advice.

Common mistakes

• Entering glucose in mmol/L. The formula expects mg/dL, so 33.3 mmol/L must be converted to about 600 mg/dL first; typing 33 produces a small negative correction.
• Typing the corrected value back in as the measured sodium, which corrects it twice.
• Expecting the correction to matter at normal glucose. At 100 to 120 mg/dL it changes sodium by well under 1 mEq/L.
• Using the result as a diagnosis. It is a single-factor estimate; a normal corrected value does not replace clinical assessment.
• Mixing units for sodium. Use mEq/L or the equal mmol/L figure, not mg/dL.