Priming Sugar Calculator
Exact priming sugar for bottle conditioning to a target CO2 level, with keg pressure too.
Safety: over-priming is the one way a brewing calculator can hurt you - too much sugar makes bottles burst. Standard beer bottles are rated to roughly 4 volumes of CO₂; stay below that, weigh (don't scoop) your sugar, and make sure fermentation is fully finished before bottling.
How it works
The beer already contains residual CO₂ that depends on its temperature. We subtract that from your target carbonation and convert the shortfall into grams of your chosen sugar. The keg pressure figure is the regulator setting to reach the same target by forced carbonation at the same temperature.
residual CO₂ = 3.0378 − 0.050062·T + 0.00026555·T² (T in °F)
sugar (g) = (target − residual) × 1.969 × litres / yield
Sources: priming and residual-CO₂ formulas per Brewer's Friend and Top Down Brew.
Frequently asked questions
- How much priming sugar per bottle?
- It depends on batch volume, beer temperature and your target carbonation level - not a fixed per-bottle amount. Enter those three and this tool gives the total sugar; weigh it rather than measuring by volume for accuracy.
- Why does temperature matter for priming?
- Beer already holds dissolved CO₂, and warmer beer holds less. The calculator subtracts that residual CO₂ (based on the highest temperature the beer reached) from your target so you do not over- or under-prime.
- Corn sugar vs table sugar vs DME?
- Each yields a different amount of CO₂ per gram, so you need different weights for the same carbonation. Table sugar is most efficient, corn sugar slightly less, dry malt extract least. Switch the sugar type to see the right weight.