Calcium mmol/L → mg/dL
Convert total or ionised calcium from mmol/L to mg/dL
Sources last checked: 2026-10-13
Calcium mmol/L → mg/dL
Convert total or ionised calcium from mmol/L to mg/dL
Converts units only. Total calcium depends on albumin; ionised calcium is preferred when protein binding is abnormal.
What is the Calcium mmol/L → mg/dL?
Calcium is reported in mmol/L in most of Europe and in mg/dL in Germany (partly), Austria, Turkey and the USA. With a molar mass of 40.08 g/mol, 1 mmol/L equals 4.008 mg/dL; the AMA SI table rounds the inverse factor to 0.25.
When to use it
- Using the albumin-corrected calcium formula, which is defined in mg/dL
- Comparing results across labs and literature
- Hypercalcaemia or hypocalcaemia thresholds given in the other unit
When not to use it
- Ionised versus total calcium — the conversion does not turn one into the other
- Urinary calcium reported per 24 h (mmol/24 h), which also needs volume
How it is calculated
Calcium (mg/dL) = calcium (mmol/L) × 4.008 (molar mass 40.08 g/mol; the AMA table rounds the inverse factor to 0.25)
Clinical pearls and limitations
- Converts units only. Total calcium depends on albumin; ionised calcium is preferred when protein binding is abnormal.
- 2.2–2.6 mmol/L ≈ 8.8–10.4 mg/dL (typical total calcium range).
- Ionised calcium 1.15–1.30 mmol/L ≈ 4.6–5.2 mg/dL.
- For total calcium in mEq/L, multiply mmol/L by 2 (divalent ion).
Frequently asked questions
How do I convert calcium from mmol/L to mg/dL?
Multiply by 4.008 (≈ 4). Example: 2.4 mmol/L = 9.6 mg/dL.
What is 2.5 mmol/L calcium in mg/dL?
10.0 mg/dL.
Do I need to correct calcium for albumin?
Total calcium falls with low albumin; use the corrected calcium calculator or measure ionised calcium.
Evidence and guidelines
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<p><a href="https://medelix.ai/en/calculators/calcium-mmol-l-to-mg-dl">Calcium mmol/L → mg/dL calculator by Medelix</a></p>For healthcare professionals and medical students. These tools support, and do not replace, clinical judgement. Always check results against the original source and your local protocols.