Weill Cornell Medicine Care Discover Teach

Calcium Equivalents

All calculations should be independently verified prior to clinical use. These calculators are intended to supplement, not replace, clinical judgment.

Convert between elemental calcium units (mg, mEq, mmol) and common calcium salt forms. Enter a value in any row and click Calculate in that row to populate all other fields.

Form Amount
Elemental calcium
Elemental Ca mg
Elemental Ca mEq
Elemental Ca mmol
Calcium salts
Calcium chloride g
Calcium chloride 10% mL
Calcium gluconate g
Calcium gluconate 10% mL
Calcium acetate g
Calcium carbonate g
Calcium citrate g
Calcium glubionate g

Calcium can be measured by the amount of the calcium salt (mg of the cation plus anion, or mL of a specified concentration) or as elemental calcium in mg, mEq, or mmol. Because calcium has a valence of +2, mEq equals twice the number of mmol. The varied units and conversion factors are a known source of medication errors.

Elemental calcium content per gram of each salt:

Salt Per mEq Ca mg Ca mmol Ca
Calcium acetate 1 g 12.6 253 6.30
Calcium carbonate 1 g 19.9 400 9.96
Calcium citrate 1 g 10.5 211 5.26
Calcium chloride 1 g 13.6 273 6.80
Calcium glubionate 1 g 3.29 66 1.64
Calcium gluconate 1 g 4.65 93 2.32

Note: rounding errors may accumulate with multiple sequential conversions.

References

  1. Kraft MD, Btaiche IF, Sacks GS, Kudsk KA. Treatment of electrolyte disorders in adult patients in the intensive care unit. Am J Health Syst Pharm. 2005;62(16):1663–1682.
  2. Trissel LA. Handbook on Injectable Drugs. 17th ed. American Society of Health-System Pharmacists; 2013.