Priming Sugar Calculator — Homebrew Carbonation
Bottle conditioning requires precise priming sugar to hit your target carbonation without over-pressuring bottles. Enter your batch volume, target CO₂ volumes, and the highest fermentation temperature to get the exact sugar weight for corn sugar, table sugar, or dry malt extract.
L
volumes CO₂
°C
Priming sugar type
Add to bottling bucket just before filling
- 1
Convert fermentation temperature to °F
20 × 9 ÷ 5 + 32 = 68 - 2
Residual CO₂ at fermentation temperature
3.0378 − 0.050062 × 68 + 0.00026555 × 68² = 0.8615Empirical polynomial in °F describing CO₂ solubility at the fermentation peak. - 3
CO₂ volumes to add from priming sugar
2.4 − 0.8615 = 1.5385 - 4
Priming sugar needed
1.5385 × 20 L × 4.28 g/L/vol = 131.7
How does this calculator work?
Beer retains dissolved CO₂ from fermentation; how much depends on peak fermentation temperature. The priming sugar weight equals (Target CO₂ − Residual CO₂) × batch volume (L) × a sugar factor (4.28 for corn sugar, 4.07 for table sugar, 5.27 for DME). Use the fermentation peak temperature for accuracy.
Formula
How this is calculated
Beer always retains some dissolved CO₂ from fermentation — the exact amount depends on the highest temperature the beer reached during active fermentation (Henry's law: warmer beer holds less gas). The residual CO₂ is calculated from a standard empirical polynomial (T in °F) derived from solubility data. Any additional carbonation must come from the priming sugar you add at bottling.
The sugar factor converts volume of CO₂ to weight of sugar: corn sugar (dextrose monohydrate) needs 4.28 g/L/vol, table sugar (sucrose) slightly less at 4.07 g/L/vol because it is more fermentable by weight, and dry malt extract requires 5.27 g/L/vol because only around 75–80% is fermentable. Yeast consumes the sugar in the sealed bottle and produces the extra CO₂ and a small amount of alcohol.
Use the fermentation peak temperature rather than conditioning or cold-crash temperature — once the yeast has finished, CO₂ already released from solution does not dissolve back in significant quantities. If your residual CO₂ already exceeds the target, no priming sugar is needed (the result is 0 g) and you should consider degassing or adjusting targets.
Frequently asked questions
It depends on the style. British and Irish ales are traditionally lightly carbonated at 1.5–2.2 volumes; American ales and most lagers sit at 2.2–2.7; Belgian ales and wheat beers go higher at 2.5–3.5; highly effervescent styles like gueuze reach 3.5–4.5 volumes. Check style guidelines for the target range.
CO₂ solubility in liquid decreases as temperature rises. Beer fermented at 20°C retains more dissolved CO₂ than beer fermented at 25°C. Using the wrong (too low) temperature in the formula would overestimate residual CO₂ and lead to under-carbonated beer; too high would give flat-tasting results. Use the highest temperature reached during active fermentation.
Yes, but the calculation is more complex. Honey is roughly 70–80% fermentable sugars, and its composition varies by variety. Fruit juice fermentability depends on the sugar profile. For reliable results, use a known pure sugar (dextrose or sucrose). If using honey, an approximate factor is 5.3–6.0 g/L/vol depending on variety — treat the result as an estimate and adjust through experimentation.
Also known as
TG we-Calculate Editorial Team. (2026). Priming Sugar Calculator — Homebrew Carbonation [Online calculator]. TG we-Calculate. https://we-calculate.com/calculator/priming-sugar-calculator
TG we-Calculate Editorial Team. "Priming Sugar Calculator — Homebrew Carbonation." TG we-Calculate. 2026. https://we-calculate.com/calculator/priming-sugar-calculator.
TG we-Calculate Editorial Team, "Priming Sugar Calculator — Homebrew Carbonation," TG we-Calculate, 2026. [Online]. Available: https://we-calculate.com/calculator/priming-sugar-calculator
@misc{wecalculate_priming_sugar_calculator, title = {Priming Sugar Calculator — Homebrew Carbonation}, author = {{TG we-Calculate Editorial Team}}, howpublished = {\url{https://we-calculate.com/calculator/priming-sugar-calculator}}, year = {2026}, note = {TG we-Calculate} }
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