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Bicarbonate (HCO₃⁻) Unit Converter
Bicarbonate (HCO₃⁻) is the body’s primary chemical buffer, playing a critical role in maintaining acid-base homeostasis (pH balance). It is regulated primarily by the kidneys, which reabsorb filtered bicarbonate and generate new bicarbonate to neutralize metabolic acids. In the blood, it acts as a proton acceptor to buffer excess hydrogen ions.
Measuring serum bicarbonate (often reported as “Total CO2” in venous blood) is essential for diagnosing acid-base disorders. Low levels suggest Metabolic Acidosis (e.g., diabetic ketoacidosis, lactic acidosis, renal failure, or diarrhea), while high levels indicate Metabolic Alkalosis (e.g., prolonged vomiting, diuretic use). This converter switches between the standard molar/equivalent units (mmol/L, mEq/L) and mass-based units (mg/dL).
SI / Standard
RecommendedMillimoles or Milliequivalents per liter.
Mass Units
Clinical Context
Reference Range: In adults, serum bicarbonate typically ranges from 22 – 29 mmol/L (mEq/L). Children often have slightly lower levels.
Bicarbonate is a key component in calculating the Anion Gap ($Na^+ – (Cl^- + HCO_3^-)$). A low bicarbonate with a high anion gap suggests the presence of unmeasured anions (like ketones or lactate). A low bicarbonate with a normal anion gap suggests bicarbonate loss (e.g., diarrhea). The conversion factor uses the molecular weight 61.02 g/mol: 1 mmol/L ≈ 6.1 mg/dL.
Clinical References
How to Use This Calculator
Follow these steps to get accurate clinical conversions instantly.
Enter Values
Input your laboratory results into the corresponding unit field (e.g., mmol/L). You can use either dot or comma decimals.
Automatic Conversion
The calculator works in real-time. As you type in one field, all other units (like mg/dL) are instantly updated.
Verify Units
Check the SI Units section. Note that mmol/L and mEq/L are identical for Bicarbonate.
Reset
Use the Clear button to reset all fields before starting a new calculation.
Frequently Asked Questions & Tips
Yes. Because the valency of the bicarbonate ion is 1, one millimole equals one milliequivalent.
Yes. In a venous serum sample, Total CO2 is composed of ~95% Bicarbonate, so they are used interchangeably in clinical practice.