Bicarbonate mmol/L to mEq/L Converter
Instantly convert bicarbonate (HCO3-) between mmol/L and mEq/L. Because bicarbonate is monovalent, the units are numerically equal — this tool also flags normal, low, and high reference ranges.
mmol/L to mEq/L, mEq/L to mmol/L, or Full Chart?
Whether you’re converting a single lab value, working backwards from mEq/L, or need a full reference chart, pick the tool below to get an instant result with a normal-range check.
Bicarbonate mmol/L to mEq/L
Enter your bicarbonate reading in mmol/L
Enter the lab value as reported in mmol/L
Reference ranges vary slightly between labs
Conversion Result
mEq/L value and reference-range status
Enter a bicarbonate value in mmol/L, then click Convert to mEq/L.
Bicarbonate mEq/L to mmol/L
Enter your bicarbonate reading in mEq/L
Enter the lab value as reported in mEq/L
Reference ranges vary slightly between labs
Conversion Result
mmol/L value and reference-range status
Enter a bicarbonate value in mEq/L, then click Convert to mmol/L.
Conversion Chart Builder
Generate a bicarbonate mmol/L-to-mEq/L table across a range
Conversion Table
mmol/L mapped to mEq/L across your range
Set a range and increment, then click Build Conversion Chart.
Bicarbonate Conversion & Ranges
Because bicarbonate (HCO3-) has a valence of 1, mmol/L and mEq/L values are always identical. Reference ranges below are typical for adults; always confirm against your lab’s own range.
| mmol/L | mEq/L | Interpretation |
|---|---|---|
| < 18 | < 18 | Markedly low — possible severe metabolic acidosis |
| 18–21 | 18–21 | Low — possible metabolic acidosis |
| 22–29 | 22–29 | Normal adult reference range |
| 30–35 | 30–35 | High — possible metabolic alkalosis |
| > 35 | > 35 | Markedly high — possible severe alkalosis |
| 1 mmol/L | 1 mEq/L | Valence of HCO3⁻ = 1, so units match 1:1 |
Bicarbonate Conversion FAQ
Everything people ask about converting bicarbonate between mmol/L and mEq/L.
For bicarbonate (HCO3-), mmol/L and mEq/L are numerically identical because bicarbonate is a monovalent ion with a valence of 1. The formula is mEq/L = mmol/L x valence, and since valence = 1 for HCO3-, mEq/L = mmol/L. A reading of 24 mmol/L is the same as 24 mEq/L.
The conversion between mmol/L and mEq/L depends on an ion’s valence (charge). Bicarbonate (HCO3-) carries a single negative charge, so its valence is 1 and the two units match exactly. Divalent ions like calcium (Ca2+) or magnesium (Mg2+) have a valence of 2, so their mEq/L value is double their mmol/L value.
A typical normal range for serum bicarbonate is about 22 to 29 mEq/L (or mmol/L, since the units match) in adults, though exact reference ranges vary slightly by laboratory. Levels outside this range may indicate a metabolic or respiratory acid-base disturbance and should be interpreted by a clinician.
A millimole (mmol) measures the amount of a substance, while a milliequivalent (mEq) measures the amount of electrical charge that substance carries. For ions with a valence of 1 (like sodium, potassium, chloride, and bicarbonate), 1 mmol equals 1 mEq. For ions with a valence of 2 or more, the mEq value is higher than the mmol value.
Yes, bicarbonate and HCO3- refer to the same ion. It is commonly measured in blood chemistry panels as part of the electrolyte or basic metabolic panel, and is reported in either mmol/L or mEq/L, which are equivalent values for this ion.
This tool is set for bicarbonate’s valence of 1, so it is accurate for sodium, potassium, chloride, and bicarbonate, which all have a valence of 1. For divalent ions such as calcium or magnesium (valence 2), you would need to multiply the mmol/L value by 2 instead of 1 to get mEq/L.