Beer Priming & Carbonation Calculator
Calculate the exact amount of priming sugar needed to carbonate your bottled homebrew to your target CO2 volumes. This calculator accounts for the residual CO2 already dissolved in your beer at bottling temperature and supports five common priming sugars including corn sugar, table sugar, DME, honey, and brown sugar.
Results
Why does temperature matter for priming?
Warm beer holds less dissolved CO2 than cold beer. The "residual CO2" already in solution depends on the highest temperature your beer reached during fermentation — not the current temperature at bottling. If you ferment at 68°F and chill before bottling, you still use 68°F for the calculation because the CO2 escaped when it was warm.
Using a too-low temperature in this calculator will produce overcarbonated beer and gushers (or bottle bombs). When in doubt, err on the side of the higher temperature the beer experienced.
CO2 Volume Reference by Style
| Style | Target CO2 (volumes) |
|---|---|
| British / English Ales (cask) | 1.50 – 1.75 |
| Scottish Ales | 1.60 – 2.00 |
| American Ales (Pale, IPA) | 2.20 – 2.60 |
| American Lager | 2.50 – 2.80 |
| German Lager (Pilsner, Helles) | 2.40 – 2.70 |
| Hefeweizen / Wheat Beers | 3.30 – 4.50 |
| Belgian Ales (Trappist, Saison) | 2.50 – 3.50 |
| Belgian Lambic / Gueuze | 2.40 – 2.80 |
| Stout / Porter | 1.80 – 2.40 |
| Cider | 3.00 – 4.50 |
How This Calculator Works
Bottle carbonation is the yeast eating a measured dose of priming sugar and producing CO2 in a sealed bottle. To hit a target, the calculator first works out how much CO2 your beer already holds — the residual CO2 — using the ProMash/Daniels relationship to the warmest temperature your beer reached: residual = 3.0378 − 0.050062·T + 0.00026555·T², with T in °F.
It then needs to add the difference up to your target: CO2 to add = target volumes − residual. As a baseline, corn sugar yields about 4 grams per liter for each additional volume of CO2, so grams = (CO2 to add) × 4.0 × liters ÷ sugar factor. The sugar factor adjusts for the fermentable yield of each sugar — sucrose, DME, honey, and brown sugar differ from dextrose — and the result is also shown in ounces and approximate cups.
A Worked Example
Carbonate a 5-gallon (18.93 L) American pale ale to 2.4 volumes with corn sugar, where the beer peaked at 68°F during fermentation.
Residual CO2 = 3.0378 − (0.050062 × 68) + (0.00026555 × 68²) = 3.0378 − 3.404 + 1.228 ≈ 0.86 volumes. CO2 to add = 2.4 − 0.86 = 1.54 volumes. Grams = 1.54 × 4.0 × 18.93 ≈ 117 g of corn sugar, about 4.1 oz. Switch to table sugar (a more efficient factor) and you would need roughly 107 g for the same carbonation. Had you mistakenly entered 40°F, residual would read about 1.46 volumes, the calculator would call for far less sugar, and the beer would finish flat.
What Affects Your Result
- Peak beer temperature — sets residual CO2 and is the most common source of error; always use the warmest point, not bottling-day temperature.
- Target CO2 volumes — style-dependent; wheat beers and Belgians want far more CO2 than English ales or stouts.
- Sugar type — dextrose, sucrose, DME, honey, and brown sugar have different fermentable yields, so the gram dose changes with your selection.
- Accurate batch volume — priming is dosed per liter, so over- or under-estimating your packaged volume scales the error directly.
- Fully attenuated beer — residual fermentable sugar from an unfinished fermentation adds uncounted CO2 and risks gushers or bottle bombs.
- Conditioning temperature and time — yeast need warmth (about 68–72°F) and two to three weeks to ferment the priming sugar completely.
Frequently Asked Questions
Which temperature do I enter at bottling?
The highest temperature the beer reached, not bottling-day temperature. CO2 escapes as beer warms and does not re-dissolve when it cools, so a beer fermented at 68°F and cold-crashed to 38°F still uses 68°F. Entering the cold number under-primes the batch.
How long does bottle conditioning take?
Most ales carbonate in two to three weeks at 68–72°F. Bottles stored cold carbonate slowly or stall. Give them two weeks, chill one, and taste; if flat, warm the rest another week. Strong beers can take a month or more.
Can I use table sugar instead of corn sugar?
Yes. Sucrose is slightly more efficient by weight than dextrose, so you need a little less; just select it and use the figure shown. The old cidery-flavor worry is debunked — priming amounts are far too small to taste.
Why did my bottles overcarbonate or become gushers?
Usually bottling before fermentation finished (extra sugar adds CO2) or entering too low a temperature (over-dosing the sugar). Wild yeast from poor cleaning can also do it. Confirm a stable final gravity over two to three days and use the warmest temperature.