Convert mEq/L to mmol/L (and back)
How to convert a value from your report into other units — with the formula and examples.
mEq/L=mmol/L
mmol/L = mEq/L ÷ z, where z is the ion's valence
How it works
Milliequivalents take the ion's charge into account. For monovalent ions (sodium Na⁺, potassium K⁺, chloride Cl⁻) the numbers are the same: 140 mEq/L of sodium = 140 mmol/L. For divalent ions (calcium Ca²⁺, magnesium Mg²⁺) the value in mmol/L is half as large: 5 mEq/L of calcium = 2.5 mmol/L.
Examples for common markers
| Marker | Molar mass / valence | Conversion example |
|---|---|---|
| Sodium Na⁺ | z = 1 | 140 mEq/L = 140 mmol/L |
| Potassium K⁺ | z = 1 | 4.5 mEq/L = 4.5 mmol/L |
| Calcium Ca²⁺ | z = 2 | 5 mEq/L = 2.5 mmol/L |
| Magnesium Mg²⁺ | z = 2 | 2.4 mEq/L = 1.2 mmol/L |
Valence z of common ions: Na, K, Cl — 1; Ca, Mg, sulfate — 2; phosphate — depends on pH (~1.8 on average).