Corrected Calcium Calculator

Adjust total serum calcium for serum albumin using the corrected calcium formula.

Aug 31, 2026 Clinical Chemistry #electrolytes #calcium #albumin

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All fields required unless noted

Total serum calcium (mg/dL)

Serum albumin (g/dL)

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Enter your values and press Calculate to see the result.

Reference Ranges Used

Calcium - Adult 8.5–10.2 mg/dL

Formula & Clinical Notes

Formula

Corrected Ca = Measured Ca + 0.8 × (4 − Albumin)

Clinical Notes

Because roughly half of serum calcium is albumin-bound, hypoalbuminemia falsely lowers total calcium. The corrected calcium adds 0.8 mg/dL for every 1.0 g/dL the albumin is below 4.0 g/dL. Correction is imperfect in critical illness and CKD, where ionized calcium is preferred.

Sources

StatPearls — Hypercalcemia
Endotext — Calcium Homeostasis and Disorders