Calcium unit converter
Convert calcium between mg/dL, mmol/L, mg/L and mEq/L. Type in either box. The factors come from our catalog and are checked by code.
AI-verified against cited sources. Awaiting expert reviewLast reviewed 2026-10-03
1 mg/dL = 0.2495 mmol/L. Nothing you type here leaves your browser.
The conversion
- 1 mg/dL = 0.2495 mmol/LFrom mg/dL to mmol/L: divide by 4.008. Back again: multiply by 4.008.
- 1 mg/dL = 10 mg/LFrom mg/dL to mg/L: multiply by 10. Back again: divide by 10.
- 1 mg/dL = 0.499 mEq/LFrom mg/dL to mEq/L: divide by 2.004. Back again: multiply by 2.004.
Mass and molar units are linked by the molecular weight: 40.08 g/mol (Calcium (Ca), atomic weight). Source: PubChem, National Library of Medicine.
Common values
From zero to about twice the usual upper limit, plus the usual limits themselves.
| mg/dL | mmol/L | mg/L | mEq/L |
|---|---|---|---|
| 2.5 | 0.62 | 25 | 1.2 |
| 5 | 1.25 | 50 | 2.5 |
| 7.5 | 1.87 | 75 | 3.7 |
| 8.6 | 2.15 | 86 | 4.3 |
| 8.7 | 2.17 | 87 | 4.3 |
| 10 | 2.5 | 100 | 5 |
| 10.2 | 2.54 | 102 | 5.1 |
| 10.3 | 2.57 | 103 | 5.1 |
| 12.5 | 3.12 | 125 | 6.2 |
| 15 | 3.74 | 150 | 7.5 |
| 17.5 | 4.37 | 175 | 8.7 |
| 20 | 4.99 | 200 | 10 |
Usual ranges in each unit
What labs print as the reference range, by who was tested. Sources for each range are on the Calcium page.
| Who | mg/dL | mmol/L | mg/L | mEq/L |
|---|---|---|---|---|
| 18–59 | 8.7–10.2 | 2.17–2.54 | 87–102 | 4.3–5.1 |
| Men, 60+ | 8.6–10.2 | 2.15–2.54 | 86–102 | 4.3–5.1 |
| Women, 60+ | 8.7–10.3 | 2.17–2.57 | 87–103 | 4.3–5.1 |
| 12–17 | 8.9–10.4 | 2.22–2.59 | 89–104 | 4.4–5.2 |
| 2–11 | 9.1–10.5 | 2.27–2.62 | 91–105 | 4.5–5.2 |