United KingdomTier 1
Priming sugar calculator
Batch volume, temperature and target carbonation in. Grams of priming sugar out.
Free·No sign-up·Last checked 2026-08-27
Formula
CO₂ residual = 3.0378 − 0.050062 × T + 0.00026555 × T² (T in °F, converted from °C)
Dextrose (g) = 4.014 × volume_L × (target CO₂ − residual CO₂)
Table sugar = dextrose × 0.909. DME = dextrose × 1.47.
Worked example. 19 L at 20°C (68°F) targeting 2.4 volumes → residual ≈ 0.86 vol, needs 117 g dextrose.
Method
Metric-native residual CO₂ formula
The residual-CO₂ regression was originally fitted in °F, so this calculator converts your °C reading internally before applying it — the 4.014 g/L constant is the correct metric-native equivalent of the imperial 15.195 g/US-gallon constant used by American calculators, not a rough approximation.
Questions
Beer already holds dissolved CO2 from fermentation, and warmer beer holds less. Use the highest temperature the beer reached after fermentation finished, not the current temperature, since that sets how much residual CO2 is actually in solution.
About 2.2–2.5 volumes suits most ales, 2.5–2.8 fits German lagers and wheat beers, and 2.8–3.2 fits Belgian styles. Check style guidelines for anything unusual.
Table sugar (sucrose) is fully fermentable and slightly more potent by weight than dextrose (which carries bound water). Dried malt extract is only partly fermentable sugar by weight, so it takes the most.