About the Priming Sugar Calculator
This priming sugar calculator tells you how much sugar to add to a batch of homebrew at bottling so that it carbonates to the level you want — from the gentle sparkle of an English bitter to the lively fizz of a German hefeweizen. Enter the volume of beer you are bottling, the warmest temperature it reached after fermentation finished, your target carbonation in volumes of CO2 and the sugar you are using.
Some CO2 is already dissolved in the beer when you bottle, and how much depends on temperature: cold-fermented lagers hold more, warm ales less. The calculator estimates that residual CO2 first, so you only add enough sugar for the difference — skipping this step is the most common cause of over-carbonated “gushers”.
Results are given for corn sugar (dextrose), table sugar, dry malt extract and honey, plus an average dose per bottle. Make sure fermentation is truly finished (a stable gravity over two or three days) before bottling, and dissolve the sugar in a little boiled water so it mixes evenly.
With the default inputs, the priming sugar to add is 124 g. Change any value above to recalculate instantly.
How to use the priming sugar calculator
- 1Measure the volume of beer you will actually bottle (after leaving trub behind).
- 2Enter the warmest temperature the beer reached once fermentation finished.
- 3Choose a target carbonation for your style from the table.
- 4Pick your priming sugar and weigh out the amount shown.
- 5Dissolve it in boiled water, mix gently into the beer and bottle; condition 2–3 weeks at room temperature.
Formula and method
Residual CO₂ is estimated from the warmest temperature T (°F) the beer reached after fermentation, using the widely used solubility fit for beer at atmospheric pressure (about 0.86 volumes at 68°F, 1.2 volumes at 50°F). Priming only has to make up the difference between that and your target.
Each gram of corn sugar per US gallon produces roughly 1/15.2 of a volume of CO₂, the constant used by most homebrewing calculators (Tinseth). Other sugars are scaled by how much fermentable sugar they contain relative to dextrose: table sugar about 0.91×, honey about 1.25× and dry malt extract about 1.47× the weight. These are averages — honey and DME vary by product.
- T
- Warmest beer temperature after fermentation, °F
- target
- Desired carbonation in volumes of CO₂
- factor
- Weight of the chosen sugar relative to corn sugar
Worked examples
5 gallons of pale ale primed with corn sugar
At 68°F the beer holds about 0.86 volumes of CO₂, so priming adds 1.64 volumes to reach 2.5. That takes 15.195 × 5 × 1.6385 ≈ 124 g (4.4 oz) of corn sugar, or about 2.3 g in each of the ~54 bottles.
20 litres of lager at 50°F with table sugar
Twenty litres is 5.28 US gallons. A lager kept at 50°F still holds about 1.2 volumes, so only 1.4 volumes need to come from sugar: 15.195 × 5.28 × 1.40 × 0.91 ≈ 102 g of table sugar, enough for 40 half-litre bottles.
Hefeweizen at 3.5 volumes with DME
At 64°F about 0.92 volumes remain, so priming must add 2.58 volumes. With dry malt extract (≈1.47× corn sugar) that is about 288 g — use pressure-rated bottles at this carbonation.
Frequently asked questions
How much priming sugar for 5 gallons of beer?+
For a typical ale fermented around 68°F and carbonated to 2.5 volumes, about 124 g (4.4 oz) of corn sugar or 113 g (4 oz) of table sugar. Lower-carbonation British styles need roughly half that.
Can I use table sugar instead of corn sugar?+
Yes. Plain white sucrose ferments completely and leaves no flavor at these doses. Use about 9% less by weight than corn sugar because sucrose yields a little more CO₂ per gram.
Why does temperature matter for priming?+
Cold beer holds more dissolved CO₂. A lager that sat at 50°F already contains about 1.2 volumes, while an ale that reached 70°F holds about 0.83, so the lager needs noticeably less sugar for the same final fizz.
How long does bottle conditioning take?+
Keep bottles at roughly 68–75°F for two to three weeks so the yeast can ferment the priming sugar, then chill them for a few days before serving. Higher-gravity beers and lagers can take longer.
What are volumes of CO₂?+
One volume means the beer contains as much carbon dioxide as its own volume would hold as a gas at standard temperature and pressure. Most commercial American beers sit around 2.5–2.7 volumes.