Anion Gap Calculator
Calculate the anion gap from serum electrolytes (sodium, chloride, bicarbonate) to assess acid-base disorders and metabolic imbalances.
Step 1: Enter Electrolyte Values
About Anion Gap
The anion gap is calculated as: Na⁺ – (Cl⁻ + HCO₃⁻). Normal range is 8-16 mEq/L. Including potassium: (Na⁺ + K⁺) – (Cl⁻ + HCO₃⁻).
Step 2: Patient Information
Clinical Significance
Anion gap helps differentiate causes of metabolic acidosis. High anion gap suggests accumulation of unmeasured anions (lactate, ketones, toxins).
Anion Gap Calculation Results
Calculated Anion Gap
Clinical Interpretation
Normal Anion Gap Metabolic Acidosis
With an anion gap of 14 mEq/L (normal range: 8-16 mEq/L), this represents a normal anion gap. Consider hyperchloremic metabolic acidosis if acidosis is present.
Common Causes Based on Anion Gap
| Anion Gap Level | Common Causes | Clinical Significance |
|---|---|---|
| Normal (8-16 mEq/L) | Diarrhea, renal tubular acidosis, ureteral diversions | Hyperchloremic metabolic acidosis |
| High (>16 mEq/L) | Lactic acidosis, ketoacidosis, renal failure, toxins | Accumulation of unmeasured anions |
| Low (<8 mEq/L) | Hypoalbuminemia, multiple myeloma, lithium toxicity | Decreased unmeasured anions or increased unmeasured cations |
Reference Ranges & Formulas
Normal Electrolyte Ranges
| Electrolyte | Normal Range (mEq/L) | Critical Values |
|---|---|---|
| Sodium (Na⁺) | 135-145 | <120 or >160 |
| Potassium (K⁺) | 3.5-5.0 | <2.5 or >6.5 |
| Chloride (Cl⁻) | 98-106 | <80 or >115 |
| Bicarbonate (HCO₃⁻) | 22-28 | <10 or >40 |
Important Medical Disclaimer
This calculator is for educational purposes only. Always consult a healthcare professional for medical advice, diagnosis, or treatment. Do not use this information to self-diagnose or self-treat medical conditions.
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