Estimate residual CO₂
The highest beer temperature is used to estimate how much fermentation CO₂ remains dissolved.
Homebrew bottling tool
Bottle Conditioning Calculator
Calculate the exact amount of priming sugar needed to carbonate your bottle-conditioned beer.
Calculate Priming Sugar
Safety Notes
Confirm fermentation is completebefore bottling.
Measure priming sugar by weightfor repeatable results.
Use pressure-rated bottlesfor your target carbonation.
Calculation method
How the Bottle Conditioning Calculator Works
The calculator estimates the CO₂ already dissolved in the beer, then calculates only the additional fermentable sugar needed to reach your selected carbonation level.
Find the CO₂ shortfall
The estimated residual amount is subtracted from your target carbonation.
Adjust for sugar type
The base result is adjusted for sucrose, dextrose, or the lower attenuation of DME.
Useful starting points
Typical Carbonation by Beer Style
| Beer style | Typical range | Calculator preset |
|---|---|---|
| British Ale | 1.5–2.0 volumes | 1.8 |
| Porter / Stout | 1.7–2.3 volumes | 2.1 |
| American Ale | 2.2–2.7 volumes | 2.4 |
| Lager | 2.2–2.7 volumes | 2.6 |
| Wheat Beer | 2.8–4.0 volumes | 3.0 |
| Belgian Ale | 2.4–3.5 volumes | 3.0 |
Common questions
Bottle Conditioning FAQ
Which beer temperature should I enter?
Use the highest temperature the beer reached during or after fermentation. This provides a practical estimate of the CO₂ retained before packaging.
Should I measure priming sugar by weight?
Yes. A digital scale is more repeatable than cups or spoons because granulated ingredients can settle and trap air.
Why does DME require more weight?
DME is not treated as fully fermentable in this calculator, so more material is required to create the same amount of CO₂.
Can I add the sugar directly to each bottle?
This MVP calculates the total batch amount. Dissolving it and mixing it evenly through a bottling bucket provides more consistent dosing.