mmol/L to Milliequivalents/L Converter
Common Conversions
| mmol/L | mEq/L |
|---|---|
| 0.1 | 0.1×v |
| 0.5 | 0.5×v |
| 1 | 1×v |
| 2 | 2×v |
| 5 | 5×v |
| 10 | 10×v |
| 20 | 20×v |
| 50 | 50×v |
| 100 | 100×v |
| 140 | 140×v |
| 200 | 200×v |
| 500 | 500×v |
Why this conversion matters in chemistry
Critical-care calcium replacement is a typical place to need it. A 2.5 mmol/L serum calcium reading on an SI-aligned clinical-chemistry report is 5 mEq/L on a USP <797> compounding worksheet — the divalent Ca²⁺ scales by 2 between mole-based and charge-based notations. Origin of the 1 mEq per mmol per unit valence: the equivalent definition: one equivalent supplies one mole of charges. Mostly bookkeeping at the boundary of SI clinical reporting and traditional bedside electrolyte management documentation.
Formula
mEq/L = mmol/L × valence
Worked Examples
140 mmol/L Na⁺ (valence 1) = 140 mEq/L
Normal serum sodium — monovalent, identical values.
2.5 mmol/L Ca²⁺ (valence 2) = 5 mEq/L
Normal serum calcium — divalent, mEq is double the mmol.
4 mmol/L K⁺ (valence 1) = 4 mEq/L
Normal potassium — monovalent identity.
1 mmol/L Mg²⁺ (valence 2) = 2 mEq/L
Normal magnesium — divalent, mEq is double.
Frequently Asked Questions
How do I convert mmol/L to mEq/L?
Multiply by ion valence. For Na⁺ (valence 1): 140 mmol/L = 140 mEq/L. For Ca²⁺ (valence 2): 2.5 mmol/L = 5 mEq/L. The factor depends on the ion's charge.
Why do clinical labs use mEq/L?
Milliequivalents track ionic charge directly, which makes electroneutrality checks straightforward: total cation mEq must balance total anion mEq in plasma. The mole-based mmol/L doesn't carry that charge bookkeeping naturally.
Which ions have valence above 1?
Divalent: Ca²⁺, Mg²⁺, Zn²⁺, Fe²⁺. Trivalent: Al³⁺, Fe³⁺, PO₄³⁻. Monovalent: Na⁺, K⁺, Cl⁻, HCO₃⁻. The valence shows up explicitly in any equivalent-based calculation.