Priming Sugar Calculator (Bottle Carbonation)
How much priming sugar to bottle-condition beer to a target CO₂ volume — corn sugar, table sugar, DME, honey, candi syrup and 12 more — by beer style, corrected for the beer’s temperature and residual CO₂, in litres or gallons, with per-bottle doses and bottle pressure.
How it works
Residual CO₂ = 3.0378 − 0.050062·T(°F) + 0.00026555·T²; sucrose-equivalent (g) = (target − residual) × litres × 3.653 (= 15.195 g corn sugar per US gallon per volume × 0.91); sugar = sucrose-equivalent ÷ the sugar’s fermentability (dextrose 0.91, DME 0.68, honey 0.75 …)
Bottle conditioning works by giving the yeast one last, measured meal in a sealed bottle, and the carbon dioxide it makes dissolves into the beer. The beer already holds some CO₂ from fermentation — how much depends on the warmest temperature it reached, since gas solubility falls as beer warms — so the calculator subtracts that residual before working out the sugar. It then uses the dosing rule built into most homebrew priming calculators: 15.195 g of corn sugar per US gallon raises carbonation by one volume, which is 4.01 g of dextrose or about 3.65 g of table sugar per litre. Other sugars are scaled by how much fermentable sugar they carry compared with sucrose: dextrose monohydrate about 91%, dry malt extract about 68%, honey about 75%, syrups less because of their water. Pick a beer style to load its typical carbonation level — British ales sit low near 1.5–2.0 volumes, American ales and lagers around 2.4–2.6, Belgian and wheat beers 3 volumes and up. The results include the dose per litre and per bottle (for priming bottles one by one), a rough volume measure, how many bottles the batch fills, and the pressure the bottles reach while conditioning, so you know when heavy bottles are needed. Overshooting risks gushers and burst bottles; undershooting gives flat beer.
Worked example
19 L of ale that finished at 20 °C (68 °F), target 2.4 volumes with corn sugar: the residual is 3.0378 − 0.050062 × 68 + 0.00026555 × 68² = 0.86 volumes, so priming must add 1.54 volumes. Sucrose equivalent = 1.54 × 19 × 3.653 = 106.7 g; corn sugar is 91% fermentable, so 106.7 ÷ 0.91 = 117 g of dextrose (about ¾ cup), or 2.0 g per 330 mL bottle. In table sugar that is 107 g; in DME 157 g. For 5 US gallons the same settings give 4.1 oz of corn sugar.
Sources: Brewer’s Friend — Beer priming calculator and carbonation guidelines · Northern Brewer — Priming sugar calculator (carbonation by style)
Frequently asked questions
Which temperature do I enter?
The highest temperature the beer reached after active fermentation ended — that sets how much CO₂ stayed dissolved. Cold-crashing afterwards does not put gas back in.
How much priming sugar for 5 gallons?
For a typical 2.4 volumes in beer that finished at 68 °F, about 4.1 oz (117 g) of corn sugar or 3.8 oz (107 g) of table sugar. Lower-carbonated British ales need closer to 2.5–3 oz; a hefeweizen at 3.6 volumes needs about 7 oz.
Can I prime each bottle individually?
Yes — use the per-bottle figure with carbonation drops or a measured scoop, though batch priming in a bottling bucket gives more even results.
Can I use table sugar instead of corn sugar?
Yes. Table sugar ferments completely and gives the same result in the bottle; you just need about 9% less by weight than corn sugar. Brown sugar, honey and maple syrup work too but add a little flavour and vary more.
Why does this calculator give a slightly different amount from another one?
Calculators differ in the residual-CO₂ formula, the temperature they ask for, and how much CO₂ they credit to each gram of sugar. This one follows the common homebrew standard (15.195 g corn sugar per US gallon per volume); results within about 10% of each other carbonate almost the same.
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This calculator is for educational purposes. Double-check important results before acting on them.