Enter your Serum Calcium, Serum Albumin, and Normal Albumin Reference values into the Corrected Calcium Calculator to get your Corrected Calcium level, along with your Calcium Status, Albumin Difference, and the Correction Applied — so you're seeing your true calcium level, not one skewed by low albumin.
Corrected Calcium
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Calcium Status
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Albumin Difference
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Correction Applied
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About 40% of serum calcium is bound to albumin. When albumin levels are low, measured total calcium appears low even if ionized (active) calcium is normal. The corrected calcium formula estimates what total calcium would be if albumin were normal.
The normal range for corrected calcium is typically 8.5-10.5 mg/dL (2.12-2.62 mmol/L), same as total calcium. Values below 8.5 mg/dL suggest hypocalcemia, while values above 10.5 mg/dL indicate hypercalcemia.
Corrected calcium is useful for screening, but ionized calcium is more accurate for critically ill patients or when acid-base disorders are present. If available, ionized calcium is the gold standard for assessing calcium status.
Low albumin can result from liver disease, malnutrition, nephrotic syndrome, chronic illness, or protein-losing conditions. In these cases, total calcium may appear falsely low without albumin correction.
The corrected calcium formula provides a reasonable estimate but has limitations. It may not be accurate in critically ill patients, those with acid-base disorders, or when protein binding is altered by medications or disease states.
Hypocalcemia symptoms include muscle cramps, paresthesias (tingling), tetany, seizures, and cardiac arrhythmias. Chvostek's and Trousseau's signs may be positive on physical examination.
Treatment decisions should ideally be based on ionized calcium when available, along with clinical symptoms. Corrected calcium is helpful for screening, but ionized calcium better reflects the physiologically active fraction.