Keg Carbonation Calculator: Force Carbonation PSI Chart

How force carbonation works

When a keg sits under constant CO₂ pressure, CO₂ dissolves into the beer until it reaches equilibrium. The carbonation level at equilibrium depends only on two things: the pressure and the temperature of the beer. This calculator uses a widely used formula for the solubility of CO₂ in beer to find the regulator pressure for your target carbonation, or the carbonation your current pressure will produce.

\begin{aligned} P &= -16.6999 - 0.0101059\,T \\ &\quad + 0.00116512\,T^2 + 0.173354\,T\,V \\ &\quad + 4.24267\,V - 0.0684226\,V^2 \end{aligned}

where $P$ is the gauge pressure in psi, $T$ the beer temperature in °F and $V$ the carbonation in volumes of CO₂. For example, 2.5 volumes at 38 °F (3.3 °C) needs about 11.3 psi. To find the carbonation at a given pressure, the calculator solves the same equation for $V$ .

Enter the temperature of the beer itself, not of the room. Pressure is gauge pressure, as shown on your regulator.

Typical carbonation by beer style

Beer style	CO₂ volumes
British-style ales	1.5–2.0
Porter and stout	1.7–2.3
Belgian ales	1.9–2.4
American ales and lagers	2.2–2.7
Fruit lambic	3.0–4.5
German wheat beer	3.3–4.5

These are typical starting points that circulate widely among homebrewers, not fixed rules: carbonate to your taste unless you brew to a style for competition.

Inside Foambyte, carbonation targets and readings are part of each batch’s carbonation stage, so you can track pressure and temperature until the beer is ready to serve.

Reference table

Regulator pressure (psi) by beer temperature (rows) and target CO₂ volumes (columns)
Temperature \ CO₂ volumes	2.0	2.2	2.4	2.5	2.6	2.8	3.0
34 °F (1.1 °C)	4.3	6.3	8.2	9.2	10.2	12.2	14.1
36 °F (2.2 °C)	5.1	7.2	9.2	10.2	11.2	13.3	15.3
38 °F (3.3 °C)	6.0	8.1	10.2	11.3	12.3	14.4	16.5
40 °F (4.4 °C)	6.8	9.0	11.2	12.3	13.4	15.5	17.7
42 °F (5.6 °C)	7.7	10.0	12.2	13.3	14.4	16.7	18.9
45 °F (7.2 °C)	9.0	11.4	13.7	14.9	16.1	18.4	20.7
50 °F (10.0 °C)	11.3	13.8	16.3	17.6	18.8	21.3	23.8
55 °F (12.8 °C)	13.6	16.3	18.9	20.3	21.6	24.3	27.0

Frequently asked questions

What pressure should I use to carbonate a keg to 2.5 volumes?

It depends on the temperature of the beer. At 38 °F (3.3 °C) you need about 11 psi; at 45 °F (7.2 °C), about 15 psi. Use the calculator above for your exact temperature.

What does "volumes of CO₂" mean?

It is the volume of CO₂ gas, at standard temperature and pressure, dissolved in one volume of beer. Beer at 2.5 volumes holds 2.5 liters of CO₂ in every liter of beer.

Why does the temperature matter?

Cold beer holds more dissolved CO₂ than warm beer. The colder the keg, the less pressure you need to reach the same carbonation.

How long does force carbonation take?

At the pressure from this calculator, the beer slowly reaches equilibrium, which usually takes one to two weeks. Raising the pressure speeds it up, but it is easy to over-carbonate the beer that way.

Does elevation change the pressure I need?

Yes. Regulators show gauge pressure, relative to the air around them, and air pressure falls with elevation. A common rule of thumb is to add about 1 psi for every 2,000 ft (600 m) above sea level.

Keg Carbonation Calculator

Pressure to set on your regulator

Carbonation at your current pressure