This bicarbonate deficit calculator estimates the HCO3 deficit based on patient weight and current measured bicarbonate in metabolic acidosis and other conditions. Read more on the medical implications below the form.

Patient weight:*
Measured Bicarbonate HCO3 (mEq/L):*
Desired Bicarbonate HCO3 (mEq/L):*

How does this bicarbonate deficit calculator work?

This health tool allows you to determine the bicarbonate deficit according to the weight of the subject, weight that can be input in either lbs or kg. For the desired bicarbonate, the 15mEq/L value is established default but can also be customized.

Determining this body variable allows the medical specialist to consider the causes of the bicarbonate imbalance and prepare for administration of compensation treatment.

This bicarbonate deficit calculator uses the following formula to determine the HCO3 missing:

Bicarbonate deficit = 0.4 x weight in kg x (desired HCO3 - measured HCO3)

Taking the example of a patient weighing 87kg with a measured HCO3 of 10mEq/L, the bicarbonate deficit = 0.4 x 87 x (15 – 10) = 174 mEq

HCO3 health implications

HCO3 deficit is caused by the presence in the body of excessive organic or inorganic acids due to a series of causes such as:

■ High acid production in several conditions

■ Excessive acid intake

■ Acid retention

■ Conditions with loss of bases

It is often met in patients who suffer from one type of metabolic acidosis. Amongst the common symptoms there is a general state of malaise, headaches, nausea, weakness, vomiting, abdominal pain, respiratory depression or acidic urine.

There are three sources of bicarbonate:

■ Renal generation due to an increase in ammonium excretion.

■ Result of the impaired hepatic metabolism of acid anions

■ Exogenous administration of sodium bicarbonate in mineral acidosis but might prove at risk in other metabolic acidosis.

Bicarbonate compensation in metabolic acidosis is often done through the most common agent sodium bicarbonate NaHCO3.


1) Kurtz I. Acid-Base Case Studies. 2nd Ed. Trafford Publishing (2004); 68:150.

2) Sabatini S, Kurtzman NA. (2009) Bicarbonate therapy in severe metabolic acidosis. J Am Soc Nephrol; 20(4): 692-5.

20 Jul, 2015