The Weir formula is a formula used in indirect calorimetry, relating metabolic rate to oxygen consumption and carbon dioxide production. According to original source, it says:
where VO<sub>2</sub> is oxygen consumption in litres per minute and VCO<sub>2</sub> is the rate of carbon dioxide production in litres per minute. The formula can also be written for units of calories per day where VO<sub>2</sub> is oxygen consumption expressed in millilitres per minute and VCO<sub>2</sub> is the rate of carbon dioxide production in millilitres per minute.
Another source gives
This corresponds to: