Lab Calculators & Corrections

Choose the calculator that matches the derived or corrected value explicitly required by the clinical question or source you are using.

• Use Anion Gap when you have sodium, chloride and bicarbonate/total CO₂ and need the arithmetic gap.
• Use Serum Osmolality when you need calculated osmolality or, with a measured value, an osmol gap.
• Use Corrected Sodium when a current source asks for a glucose-adjusted sodium estimate in hyperglycaemia.
• Use Corrected Calcium when you specifically need to reproduce or interpret an albumin-adjusted calcium estimate.

No. They are equation-based values derived from measured laboratory inputs and should remain labelled as calculated, corrected or estimated values.

• A corrected sodium does not replace the measured sodium or serum osmolality.
• A corrected calcium is not the same as directly measured ionised calcium.
• An osmol gap depends on both the measured laboratory osmolality and the formula used for the calculated value.

Different equations, unit conventions, correction factors and laboratory methods can produce different results.

• Corrected sodium commonly uses either the Katz 1.6 or Hillier 2.4 factor.
• Serum osmolality equations vary in their glucose, urea/BUN and ethanol terms.
• Anion-gap reference intervals vary with the laboratory method and whether potassium is included.

No. MedMaths performs the selected arithmetic and explains the calculation; it does not diagnose a condition or replace clinical assessment.

• Use the calculated value with the measured laboratory data, clinical history, examination and the relevant diagnostic guidance.
• If a result is unexpected or clinically important, verify the inputs, units, equation and source before acting on it.