Corrected Calcium Calculator — Free Online Calculator
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Corrected Calcium
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About This Calculator
Corrected calcium adjusts the total serum calcium level for abnormal albumin levels. About 40% of calcium in blood is bound to albumin, so when albumin is low (hypoalbuminemia), the total calcium may appear falsely low even though ionized (active) calcium is normal. This calculator corrects for that effect.
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Interpretation
| Corrected Ca (mg/dL) | Interpretation |
|---|---|
| < 8.5 | Hypocalcemia |
| 8.5 – 10.5 | Normal |
| > 10.5 | Hypercalcemia |
Frequently Asked Questions
Why do we correct calcium for albumin?
About 40% of total serum calcium is bound to albumin. In hypoalbuminemia, total calcium appears low even when ionized (active) calcium is normal. Correcting for albumin provides a better estimate of true calcium status.
What is the formula for albumin-corrected calcium?
Corrected Calcium = Measured Total Calcium + 0.8 × (4.0 − Serum Albumin). This adds 0.8 mg/dL for each 1 g/dL decrease in albumin below the normal reference of 4.0 g/dL.
When is corrected calcium not reliable?
Corrected calcium is unreliable in critically ill patients, those with acid-base disturbances, or patients receiving large-volume transfusions. In these settings, ionized calcium measurement is preferred.
What is the normal range for corrected calcium?
The normal range for corrected calcium is typically 8.5–10.5 mg/dL (2.12–2.62 mmol/L). Values above this suggest hypercalcemia, and values below suggest hypocalcemia.
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⚠ Medical Disclaimer
This tool is for educational and informational purposes only. It is not intended to replace professional medical advice, diagnosis, or treatment. Always consult a qualified healthcare professional for clinical decisions.