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Corrected Calcium Calculator

Calculate corrected calcium levels based on albumin. Critical for patients with hypoalbuminemia.

Last updated: 2/3/2026
Data sources:MDCalc Reference

Total calcium levels can be misleading in patients with low albumin. Since roughly 40-50% of calcium is bound to albumin, low albumin levels can make calcium appear falsely low.

Calculator Inputs

mg/dL
g/dL

Results

Enter values above to see your results

How It Works

This calculator uses the Payne formula to estimate what the calcium level would be if the albumin were normal (4.0 g/dL).

Worked Examples

Patient with Calcium 8.0 and Albumin 2.5

Difference in Albumin:4.0 - 2.5= 1.5
Adjustment Factor:1.5 × 0.8= 1.2
Corrected Calcium:8.0 + 1.2= 9.2 mg/dL

Tips & Best Practices

  • Use this when albumin is < 4.0 g/dL.
  • If ionized calcium is available, that is the gold standard and correction is not needed.
  • Normal corrected calcium range is typically 8.5 - 10.2 mg/dL.

Frequently Asked Questions

What is the formula?

Corrected Ca = Measured Ca + 0.8 * (4.0 - Albumin)