Clinical tool
Corrected Calcium
Calcium corrected for serum albumin.
Enter measured calcium and albumin to see the corrected calcium.
What this calculates
Total calcium adjusted for low or high albumin: corrected calcium = measured calcium + 0.02 × (40 − albumin in g/L), in mmol/L.
When to use it
When total calcium is measured in a patient whose albumin is abnormal, and ionised calcium is not available.
How to interpret it
Reference range for corrected calcium is about 2.20 to 2.60 mmol/L (8.8 to 10.4 mg/dL). Values from 3.0 mmol/L are generally regarded as significant hypercalcaemia.
Important limitations
- Albumin correction is an approximation and is least reliable in critical illness, renal failure and acid-base disturbance.
- Ionised calcium, where available, is the more reliable measure.
- Reference ranges vary between laboratories and assays. Use your local range.
For practising medics only. Clinical tools support judgement, they do not replace it. Always verify results against current guidelines and the patient in front of you.