Keg Forced Carbonation Calculator and Chart

Forcing carbonation into kegged beer works by connecting a CO2 tank to a sealed keg and letting the gas dissolve into the beer over time, and the regulator pressure that produces a given carbonation level depends on two things: the temperature of the beer and the desired volumes of CO2. The standard formula is P = -16.6999 - 0.0101059 x T + 0.00116512 x T^2 + 0.173354 x T x V + 4.24267 x V - 0.0684226 x V^2, where T is the temperature in degrees Fahrenheit, V is the desired volumes of CO2, and P is the resulting pressure in PSI.

Desired volumes of CO2 typically fall between 2.0 and 3.0 for most beers; a beer style guide can fill in a recommended midpoint carbonation level for a chosen style rather than starting from a blank guess. Beer or keg temperature, measured inside the keg or refrigerator, typically runs 32 to 50 degrees Fahrenheit (0 to 10 degrees Celsius). Both figures feed directly into the pressure formula, so a colder keg needs a different regulator setting than a warmer one to reach the same carbonation level.

A calculator mode returns the pressure for one specific temperature and carbonation level, while a carbonation chart mode lays out a full reference grid across many temperature and pressure combinations at once, useful as a printable reference at the keg. Settings holds decimal precision and a step-by-step view substituting the entered values into the carbonation equation.

A pale ale sits at 38 degrees Fahrenheit and targets 2.4 volumes of CO2. P = -16.6999 - (0.0101059 x 38) + (0.00116512 x 38^2) + (0.173354 x 38 x 2.4) + (4.24267 x 2.4) - (0.0684226 x 2.4^2) = -16.6999 - 0.384 + 1.682 + 15.810 + 10.182 - 0.394, or about 10.2 PSI.

Force carbonation is essential for homebrewers and craft brewers who keg their beer. Knowing the correct regulator pressure eliminates guesswork and prevents over-carbonated or flat beer across the scenarios below.

• Homebrewing: Setting the CO2 regulator to the exact PSI needed for a pale ale at 38 degrees Fahrenheit with 2.4 volumes of carbonation, then waiting 10 to 14 days for full absorption, avoids both flat beer and a foamy first pour.
• Craft Brewing: Comparing regulator settings across multiple kegs stored at different temperatures keeps carbonation levels consistent throughout a taproom lineup.
• Style Matching: A built-in style guide gives the recommended carbonation range for a German wheat beer (3.3 to 4.5 volumes) or a British ale (1.5 to 2.0 volumes), setting the pressure accordingly.
• Troubleshooting: Diagnosing over-carbonation or foaming problems means checking whether the current regulator pressure matches the target volumes for the serving temperature.
• Metric Brewing: Converting between PSI and bar, or Fahrenheit and Celsius, serves brewers working with metric equipment or following European recipes.
• Quick Reference: The carbonation chart works as a printable reference at the keg without needing a phone or computer during brew day.
• Competition Preparation: Dialing in precise carbonation levels to match BJCP style guidelines matters before submitting entries to homebrew competitions.
• Education: The relationship between temperature, pressure, and dissolved CO2 becomes explicit in the formula derivation shown in step-by-step mode.