Keg Carbonation Calculator
Calculate CO2 pressure (PSI) needed to carbonate your homebrew keg to a target volumes of CO2.
Based on beer temperature and target style.
Keg carbonation uses CO2 pressure applied at a controlled temperature to dissolve a target amount of carbon dioxide into your beer. The CO2 solubility in beer follows Henry’s Law: the amount dissolved is proportional to pressure and inversely related to temperature.
Target CO2 Volumes Formula:
The relationship between pressure, temperature, and dissolved CO2 is given by the empirical formula:
Pressure (PSI) = -16.6999 + (0.0101764 × Temp°F²) + (-0.00116699 × Temp°F) + (Volumes × 29.3454)
In practice, brewers use a pre-calculated carbonation chart. The two inputs are:
- Beer temperature (°F or °C) — must be stable in the kegerator
- Target CO2 volumes — style-dependent (see below)
Typical CO2 volumes by style:
| Beer Style | CO2 Volumes |
|---|---|
| American lager | 2.5–2.8 |
| Pale ale / IPA | 2.2–2.5 |
| Stout / porter | 1.8–2.2 |
| Belgian ale | 2.8–3.5 |
| Wheat beer | 3.0–4.5 |
| Cider | 2.5–3.0 |
Worked example: Beer stored at 38°F. Target: 2.4 volumes (American pale ale) From carbonation chart: ~9–10 PSI
Set regulator to 10 PSI and wait 7–10 days at temperature for equilibrium carbonation (the most reliable method).
Forced carbonation (faster method): Set to 30 PSI for 24–36 hours while rolling the keg to agitate, then drop to serving pressure (~10–12 PSI). Results in 1–2 days rather than one week — but over-carbonation risk is higher.
Serving pressure: Typically 8–12 PSI through a 5–6 foot beer line produces a proper pour without excessive foam.