Keg Carbonation
Use this free keg carbonation calculator to find the right CO₂ pressure for your beer style and serving temperature — for force carbonating in a keg.
How to use it
- Enter your keg's temperature (fridge temp is usually 3–5°C).
- Choose your target CO₂ volumes using the style guide below.
- Set your regulator to the PSI/Bar shown.
Style & CO₂ volumes guide
| Style | CO₂ Volumes |
|---|---|
| British ales | 1.5–2.2 |
| Belgian ales | 2.0–4.5 |
| American ales | 2.2–3.0 |
| European lagers | 2.4–2.6 |
| American lagers | 2.5–2.8 |
| German weizens | 2.8–5.1 |
How long does force carbonating take?
Set your regulator to the pressure shown, and leave the keg connected for around a week for the CO₂ to fully dissolve at serving temperature. For a faster method, you can shake or rock the keg gently at a higher pressure for 10–15 minutes, then reduce back to serving pressure — but this is less precise.
More free home brew calculators
Browse our full range of King Keg pressure barrels and keg spare parts at BrewCo UK, Sowerby Bridge.
How to force carbonate a keg
What it does: this calculator gives the CO₂ pressure to set on your regulator so your beer reaches the fizz level you want at your keg temperature.
How to use it: enter the temperature of the beer in the keg, choose the carbonation level (in volumes of CO₂) for your style, and set your regulator to the pressure shown.
The formula in plain words: cold beer holds more CO₂ than warm beer. The calculator uses a standard carbonation equation that links temperature, pressure and CO₂ volumes, so the warmer the beer, the more pressure it needs to hold the same fizz.
Worked example: a pale ale at 4°C, aiming for 2.2 volumes, needs about 8.7 PSI (0.60 bar). An American IPA at 2.5 volumes at the same temperature needs about 11.9 PSI. A British bitter at 12°C and 1.5 volumes needs only about 6.3 PSI.
Leave the keg connected at that pressure for about a week. Once it's carbonated, balance your lines with the line balancing calculator so it pours without foaming.