Corrected (Albumin-Adjusted) Calcium Calculator
Corrected (albumin-adjusted) calcium accounts for the protein-binding behaviour of calcium when serum albumin is low. The standard formula adds 0.8 mg/dL to measured calcium for every 1 g/dL that albumin falls below 4 g/dL. The correction is widely used in hospital medicine because hypoalbuminaemic patients commonly show low total calcium with normal ionised calcium. Direct measurement of ionised calcium remains the gold standard when precise calcium status is needed (e.g. critical illness, citrate toxicity, parathyroid evaluation).
This tool is for educational and decision-support use only. It does not replace independent clinical judgement. Always verify against the current guideline, FDA label, or specialty reference cited below before acting. Do not enter patient identifiers (name, MRN, dates of service).
Tool
Who this is for
- Internal medicine and hospitalist trainees
- Critical care clinicians
- Endocrinology consult services
How to interpret the result
| Score / band | Interpretation |
|---|---|
| Hypocalcaemia (corrected < 8.5) | Workup for vitamin D, PTH, magnesium, renal function. |
| Normocalcaemia (8.5–10.5) | Within most reference ranges (verify your laboratory). |
| Hypercalcaemia (corrected > 10.5) | Workup for primary hyperparathyroidism, malignancy, granulomatous disease. |