Priming Sugar Calculator (Bottle Carbonation for Beer and Cider)
Grams of sugar to add to a batch before bottling to reach a target carbonation, from the volume, the fermentation temperature and the type of sugar.
Results
The dashed line marks the value you entered.
What this tool does
Beer already holds some dissolved CO₂ when fermentation ends, and the warmer it got, the less stays in solution; the empirical fit used here gives about 0.86 volumes at 20 °C. Priming sugar supplies the rest: yeast turns one molecule of sucrose into four of CO₂, or one of glucose into two, which fixes the grams of sugar per gram of gas. One 'volume' means a litre of gas at 0 °C and 1 atm per litre of beer, and most ales sit around 2 to 2.5.
Formula
residual CO₂ = 3.0378 − 0.050062 T + 0.00026555 T² (T in °F) · CO₂ to add = target − residual · 1 volume = 44.01 ÷ 22.414 g/L · sugar = CO₂ × M_sugar ÷ (n × 44.01)
Variables
| Symbol | Meaning | Unit |
|---|---|---|
vol | Volume of beer to carbonate | L |
tb | Highest temperature the beer reached after fermenting | °C |
tv | Carbonation you want | vol. CO₂ |
sg | Sugar for priming | — |
bs | Bottle size | L |
G | Priming sugar for the whole batch | g |
GL | Sugar per litre | g/L |
GB | Sugar per bottle | g |
RC | CO₂ already dissolved in the beer | vol. CO₂ |
Worked example
- Volume of beer to carbonate20 L
- Highest temperature the beer reached after fermenting20 °C
- Carbonation you want2.4 vol. CO₂
- Sugar for priming1
- Bottle size0.5 L
- Priming sugar for the whole batch117 g
- Sugar per litre5.87 g/L
- Sugar per bottle2.94 g
- CO₂ already dissolved in the beer0.86 vol. CO₂
Limitations
- The result is an estimate based only on the values you type. Real situations often include factors this calculator does not know about.
- The formula assumes ideal conditions: no friction losses, no air resistance and no efficiency losses unless you enter them.