Base Excess Unit Converter

Base excess (BE) is a calculated value from arterial blood gas analysis that measures the metabolic component of your body's acid-base balance. It represents the amount of strong acid (in mmol/L) that would need to be added to blood to return it to a normal pH of 7.40 under standardized conditions.

A positive base excess indicates an excess of base (alkalosis), while a negative value (sometimes called base deficit) indicates a deficit of base or excess of acid (acidosis). The normal range is typically -2 to +2 mEq/L.

Base excess is particularly useful because it isolates the metabolic contribution to acid-base status, independent of respiratory changes in carbon dioxide. This helps clinicians distinguish between respiratory and metabolic causes of pH disturbances.

Base excess is not produced by any organ. It is a calculated value derived from measured blood gas parameters (pH, pCO2, and hemoglobin) using the Van Slyke equation. It reflects the net effect of all buffering systems in the body, primarily bicarbonate generated by the kidneys and metabolic acids produced throughout the body.