Calcium Correction for Albumin

Correct total serum calcium for hypoalbuminemia (Payne formula).

For educational and clinical reference. Not a substitute for medical judgment. See the medical disclaimer.
Corrected Calcium

References

  1. Payne RB, Little AJ, Williams RB, Milner JR. Interpretation of serum calcium in patients with abnormal serum proteins. BMJ. 1973;4(5893):643-646.

How to use

  1. Enter total calcium and albumin.
  2. Corrected calcium appears instantly.
  3. Use direct ionized calcium when precision is critical.

Frequently asked questions

Formula?

Corrected Ca = Total Ca + 0.8 × (4 − Albumin). Reference albumin = 4 g/dL.

When to correct?

In hypoalbuminemia (cirrhosis, malnutrition, nephrotic syndrome), total calcium underestimates ionized (physiologically active) calcium. Correction is an estimate; direct ionized calcium is preferred when critical.

Normal range?

Total calcium normal range: 8.5–10.5 mg/dL.

Limitations?

The Payne correction is approximate and may be inaccurate in critical illness, end-stage renal disease, and acid–base disturbances. Ionized Ca is the gold standard.

Last updated

Powered by maratool