Corrected Calcium / Sodium Suite
Two bedside corrections in one tool.
Open the calculator → Runs in your browser. Data leaves only if you deliberately send a problem report from the interactive tool.
Example
- Measured calcium
- 8.0 mg/dL
- Albumin
- 2.0 g/dL
- Measured sodium
- 130 mEq/L
- Glucose
- 600 mg/dL
Result: Corrected Ca 9.6 mg/dL; corrected Na (Katz) 138, (Hillier) 142.
The tool opens with these values already filled in. Replace them with your own.
What you enter
- Measured calcium
- Albumin
- Measured sodium
- Glucose
What this is
Payne's albumin-corrected calcium adjusts the measured total calcium for the patient's serum albumin (corrected Ca = measured Ca + 0.8 x (4.0 - albumin)), unmasking true hypo- or hypercalcemia when albumin is abnormal. Glucose-corrected sodium adjusts the measured sodium for hyperglycemia using either the classic Katz factor (1.6 mEq/L per 100 mg/dL glucose above 100) or the Hillier factor (2.4 mEq/L per 100 mg/dL above 100); Sophie Well returns both so you can compare them against the clinical picture.
When to use it
Reach for the calcium correction whenever a total calcium is reported on an inpatient whose albumin is not 4.0 - the corrected number is the right value to compare against the laboratory's reference range, and the right value to act on for symptomatic hypocalcemia workup. Reach for the sodium correction whenever you see a sodium and a glucose drawn together with the glucose above ~200 mg/dL (DKA, HHS, severe steroid-induced hyperglycemia); the corrected sodium tells you whether the apparent hyponatremia is real dilutional, pseudo-, or true. When in doubt, an ionized calcium and a recheck after glucose normalizes are still the gold standards.
How this is calculated
Payne RB, Little AJ. Interpretation of serum calcium in patients with abnormal serum proteins. Br Med J. 1973;4(5893):643-646. Sodium: Katz MA. N Engl J Med. 1973;289(16):843-844; Hillier TA, et al. Am J Med. 1999;106(4):399-403. Read the sources: Payne 1973 (calcium) ↗, Katz 1973 (sodium) ↗, Hillier 1999 (sodium) ↗
A reference and educational tool. Not medical, legal, or financial advice, and not a substitute for clinician judgment.
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