Carbonation Volumes Calculator

How it is calculated

The tool uses a CO₂ solubility equation: V = (P + 14.695) × (0.01821 + 0.09011 × e−(T − 32) / 43.11) − 0.003342. T is the liquid temperature in degrees Fahrenheit and P the gauge pressure in psi, the number on your regulator. Adding 14.695 converts gauge to absolute pressure. The answer V is dissolved CO₂ in volumes, shown with two decimals, and it never goes below 0. Pressure cannot be negative. Higher pressure and colder liquid both raise the volumes. The value is an equilibrium figure, so the liquid must sit at that pressure and temperature long enough to absorb the gas, which can take days without agitation. Altitude changes the atmospheric pressure but is not included. Temperature must be entered in Fahrenheit, so convert from Celsius first.

Common mistakes

• Entering the temperature in Celsius. The field takes Fahrenheit, so 3 °C typed as 3 is read as 3 °F and the volumes come out far too high (5.20 at 12 psi). Convert first: °F = °C × 9/5 + 32.
• Entering pressure in bar or kPa. The field is psi gauge; 1 bar is about 14.5 psi.
• Using the temperature of the room instead of the beer. The liquid temperature matters, and a keg in a fridge is much colder than the room.
• Expecting the carbonation level straight away. The formula gives the final equilibrium, and a still keg set to 12 psi may need many days to reach it.
• Adding the 14.7 psi atmosphere yourself. The tool already does it, so enter the regulator reading directly.