Anion Gap Calculator
Calculate anion gap from serum electrolytes with albumin correction for acid-base disorder evaluation
Calculate Anion Gap
Medical Professional Use Only
This calculator is designed for healthcare professionals. Results must be interpreted with clinical context. Not for patient self-diagnosis or treatment decisions.
Primary Electrolytes (Required)
Normal: 135-145 mEq/L
Normal: 95-105 mEq/L
Normal: 22-28 mEq/L
Optional Parameters
Usually omitted due to low concentration
Important for critically ill patients
Anion Gap Results
Enter electrolyte values to calculate
Calculation Details
Reference Ranges
Example Calculation
DKA Patient Example
Laboratory Values:
• Sodium (Na⁺): 140 mEq/L
• Chloride (Cl⁻): 100 mEq/L
• Bicarbonate (HCO₃⁻): 10 mEq/L
• Albumin: 3.0 g/dL
Calculation
Standard AG = 140 - (100 + 10) = 30 mEq/L
Albumin correction = 30 + 2.5 x (4.4 - 3.0)
Corrected AG = 33.5 mEq/L
High anion gap acidosis
Clinical Significance
Acid-Base Assessment
Essential for evaluating metabolic acidosis
Differential Diagnosis
Helps identify cause of acidosis
Treatment Guidance
Guides therapeutic interventions
Quick Reference
Understanding the Anion Gap
What is the Anion Gap?
The anion gap represents the difference between measured cations and anions in blood serum. It reflects "unmeasured anions" not detected in routine electrolyte panels, helping identify the cause of metabolic acidosis.
Clinical Applications
- •Evaluate metabolic acidosis etiology
- •Monitor critically ill patients
- •Screen for toxic ingestions
- •Assess treatment response
Calculation Methods
Standard Formula
AG = [Na⁺] - ([Cl⁻] + [HCO₃⁻])
Normal range: 3-11 mEq/L
With Potassium
AG = [Na⁺] + [K⁺] - ([Cl⁻] + [HCO₃⁻])
Normal range: 5-16 mEq/L
Albumin Correction
Corrected AG = AG + 2.5 x (4.4 - [Albumin])
Important in hypoalbuminemia