Priming Sugar Calculator

Calculate how much priming sugar to add when bottling beer, in total and per bottle, from the target carbonation, beer temperature and volume.

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Target carbonation (vol)

Volumes of CO₂, e.g. 2.5 for most ales and lagers

Beer temperature (°C)

Warmest temperature the beer reached after fermentation

Beer volume (L)

Volume of beer you are bottling

Total priming sugar131gPer 355 mL (12 fl oz) bottle2.3gPriming sugar rate6.54g/LCO₂ already in the beer0.86vol

Results are estimates provided "as is," for informational and planning purposes only, without warranties of any kind. Check them before you rely on them: you are responsible for decisions about your beer and equipment, including pressure and carbonation levels, the pressure ratings of your kegs and fittings, and any alcohol content you declare. Use of this calculator is subject to our Terms and Conditions.

Plan recipes and track every batch with these calculators built in. Foambyte is free to start.

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How priming sugar is calculated

Fermented beer already holds some CO₂. How much depends on its temperature, estimated with:

\begin{aligned} C_r = {} & 3.0378 - 0.050062\,T \\ & + 0.00026555\,T^2 \end{aligned}

where $C_r$ is the residual CO₂ in volumes and $T$ the temperature in °F.

The yeast then turns the priming sugar into the rest of the CO₂ you want. Each volume of CO₂ needs 3.992 grams of sugar per liter of beer:

S = (C_t - C_r) \times 3.992

where $S$ is the sugar in grams per liter and $C_t$ the target carbonation in volumes.

For example, beer that reached 20 °C (68 °F) holds about 0.86 volumes of CO₂. To reach 2.5 volumes it needs 6.54 g/L: 131 g for 20 L of beer, or about 2.3 g per 355 mL (12 fl oz) bottle.

Inside Foambyte, priming sugar is calculated in each batch’s carbonation stage from the batch’s own volume and temperature.

Reference table

Priming sugar (g/L) by the warmest beer temperature after fermentation (rows) and target CO₂ volumes (columns), with the CO₂ already in the beer
Temperature	CO₂ in beer	2.0 vol	2.2 vol	2.4 vol	2.6 vol	2.8 vol	3.0 vol
50 °F (10.0 °C)	1.20	3.2	4.0	4.8	5.6	6.4	7.2
55 °F (12.8 °C)	1.09	3.6	4.4	5.2	6.0	6.8	7.6
60 °F (15.6 °C)	0.99	4.0	4.8	5.6	6.4	7.2	8.0
65 °F (18.3 °C)	0.91	4.4	5.2	6.0	6.8	7.6	8.4
68 °F (20.0 °C)	0.86	4.5	5.3	6.1	6.9	7.7	8.5
70 °F (21.1 °C)	0.83	4.7	5.5	6.2	7.0	7.8	8.6
72 °F (22.2 °C)	0.81	4.8	5.5	6.3	7.1	7.9	8.7
75 °F (23.9 °C)	0.78	4.9	5.7	6.5	7.3	8.1	8.9

Frequently asked questions

Which temperature should I enter?

The warmest temperature the beer reached after fermentation finished. Warm beer holds less dissolved CO₂, and the CO₂ that escaped does not come back when the beer cools, so that temperature sets how much CO₂ is left before priming.

Does the type of sugar matter?

Different sugars produce slightly different amounts of CO₂ per gram. This calculator uses a single factor of 3.992 grams per liter for each volume of CO₂, the same as the Foambyte app, and does not adjust for the sugar type.

How long does bottle conditioning take?

Usually two to three weeks at room temperature. Stronger beers and cooler rooms take longer. Chill one bottle and open it to check before you chill the rest.

How do I avoid overcarbonated or exploding bottles?

Bottle only after fermentation has finished, when the gravity stays the same over several days, weigh the sugar instead of estimating it, and mix it evenly into the beer. Use bottles made for carbonated beer and never prime above the carbonation they are rated for.