Anion Gap Formula Calculator

Calculate Anion Gap





Formula

The formula to calculate the anion gap is:

\[ \text{Anion Gap} = \text{Na}^+ - (\text{Cl}^- + \text{HCO}_3^-) \]

Where:

Example

Let's say the sodium (\( \text{Na}^+ \)) is 140 mEq/L, the chloride (\( \text{Cl}^- \)) is 100 mEq/L, and the bicarbonate (\( \text{HCO}_3^- \)) is 24 mEq/L. Using the formula:

\[ \text{Anion Gap} = 140 - (100 + 24) = 16 \text{ mEq/L} \]

So, the anion gap is 16 mEq/L.

What is Anion Gap?

The anion gap is a value calculated from the concentrations of serum electrolytes. It helps to identify the presence of metabolic acidosis and to differentiate between its causes. The normal range for the anion gap is typically 6-12 mEq/L[^1^].