Carbonation Calculator

Priming sugar depends on your target CO₂ volumes, batch temperature and sugar type: colder beer, cider or mead already holds more dissolved CO₂ (residual CO₂), so it needs less added sugar to reach the same target. This calculator accounts for that automatically.

This is expected at low targets, not a bug. Beer, cider and mead already hold dissolved CO₂ from fermentation, and how much depends only on temperature — for example, around 0.85 volumes at 20°C (68°F), rising to roughly 1.7 volumes near 0°C (32°F). The result panel's "Residual CO₂ at this temp" row shows that baseline, and "CO₂ to add" is your target minus it. If your target CO₂ is at or below the residual, no sugar is needed to get there, so the dose is 0g regardless of batch size — this holds whether you're bottling 19 liters or 10,000 liters, since the residual is a per-volume concentration, not a fixed amount. Raise the target above the residual value, or condition at a colder temperature, to see a non-zero dose.

The gauge above names the everyday drink closest to your target so the number means something concrete. As a rough guide, in volumes of CO₂, low to high: still wine (0.0–0.4 vol), cask-conditioned British ale (0.8–1.5 vol), standard canned or draft lager (2.0–2.6 vol), bottled cider (2.6–3.0 vol), Belgian-style ale (3.0–3.6 vol), cola and other sodas (3.6–4.2 vol), Champagne or sparkling wine (4.5–5.5 vol). Most bottle-conditioned homebrew beer and cider targets land between standard lager and Belgian-style ale; only push toward soda or Champagne levels if your bottles are rated to handle that pressure.

Table sugar (sucrose) and corn sugar (dextrose) are the most common and predictable. DME (dry malt extract) and honey add flavor but are less predictable and typically need more mass for the same CO₂ target. Pick whichever this calculator shows the dose for and adjust the batch to match.

It comes down to how much of what you weigh out is actually fermentable. Table sugar (sucrose) is pure and 100% fermentable, and splitting into glucose and fructose during fermentation pulls in a little water mass, so it needs the least sugar per liter of any option here. Corn sugar (dextrose), fructose and glucose are already the simple sugars sucrose breaks down into, so skipping that step costs about 5% more mass for the same CO₂ — all three take an identical, slightly higher dose. Honey needs more again because it's only roughly four-fifths sugar by weight, diluted with water and non-fermentable trace compounds, so a gram of honey carries less fermentable sugar than a gram of table sugar. DME (dry malt extract) needs the most by far: a large share of its weight is unfermentable dextrins, proteins and minerals carried over from mashing, so only part of every gram converts to CO₂.

Overpriming builds excess pressure in the bottle, which can cause gushers or, in the worst case, bottle bombs. Always weigh priming sugar rather than estimating by eye, use bottles rated for carbonation, and store conditioning bottles somewhere safe until you have confirmed carbonation levels.