Priming Sugar Calculator

Warmer beer holds less dissolved CO2, so it needs more priming sugar to reach the same fizz. The tool estimates residual CO2 as 3.0378 - 0.050062 x T + 0.00026555 x T squared, with T in Fahrenheit, then primes only for the difference between that and your target.

Use the warmest temperature the beer has reached since fermentation finished, which is usually the ambient temperature of your fermenting area. That highest point sets how much CO2 has already escaped, so entering a colder later reading would make the tool underprime.

Most ales sit near 2.2 to 2.6 volumes, British and cask styles run lower around 1.5 to 2.0, and wheat beers, saisons and many Belgians reach 3.0 or more. Match the Target CO2 field to the style you are brewing.

The result is corn sugar, also called dextrose or priming sugar. Table sugar, sucrose, is denser per gram of fermentable, so you would use roughly 0.91 times the corn sugar weight to hit the same carbonation.

If your target sits at or below the CO2 already dissolved at that temperature, no sugar is needed. The tool clamps the dose to zero grams and shows Already carbonated, which happens most often with very cold beer aimed at a low, cask-style fizz.

Yes. The degrees F and degrees C toggle converts the value in the field as you switch, so 68 F becomes 20 C. The engine always works in Fahrenheit internally, so the answer is identical either way.

No. It assumes plain corn sugar as the priming source. Dried malt extract and honey carbonate at different rates because their fermentable fraction differs, so you would need a separate conversion for those.

Yes. Too much sugar, or bottling before fermentation is truly finished, builds pressure that can burst glass. Weigh the sugar on an accurate scale, confirm a stable final gravity over several days, and stay near the recommended range for the style.

Yes. The calculation runs entirely in your browser, so your batch volumes, targets and temperatures never leave your device.