Beer that fermented warm holds less dissolved CO₂, so it needs more priming sugar. Dissolve the sugar in a little boiling water, cool it and mix it gently into the beer before bottling. Too much sugar can create dangerous bottle bombs.
How to use the Priming Sugar Calculator
- Beer style
- Target CO₂ volumes
- Batch volume
- Temperature unit
- Highest fermentation temperature
- Priming sugar
Results update as you type, and every field accepts the units shown in its menu.
How it works
Choose the beer style (or a custom CO₂ level), the batch volume, the fermentation temperature and the sugar.
Tips
- Measure gravity and temperature carefully – hydrometers are calibrated for a specific temperature.
- Keep alcohol calculations conservative: never drink and drive, and know your limits.
- Write down every measurement in a brewing log so you can repeat good batches.
- Chill drinks in an ice-water bath for the fastest, safest cooling.
Common mistakes to avoid
- Reading a hydrometer at the wrong temperature without correcting it.
- Mixing up ABV (% by volume) and ABW (% by weight).
- Over-priming bottles – too much sugar can make bottles burst.
Inputs explained
| Field | What to enter |
|---|---|
| Beer style | Choose one: British ales (bitter, mild) (1.8 vol), Porter and stout (2.1 vol), Belgian ales (2.2 vol), American pale ale / IPA (2.4 vol) … |
| Target CO₂ volumes | A number |
| Batch volume | Units: US gal, L, UK gal |
| Temperature unit | Choose one: °F, °C |
| Highest fermentation temperature | A number |
| Priming sugar | Choose one: Table sugar (sucrose), Corn sugar (dextrose), Dry malt extract, Honey |
What each result means
- CO₂ already in the beer = 3.0378 – 0.050062×[Temperature °F] + 0.00026555×[Temperature °F]^2
- Priming sugar = max(15.195×[Batch volume]÷3785.411784×([Target CO₂] – [CO₂ already in the beer])÷[Priming sugar], 0)
- Per 12 oz (355 ml) bottle = [Priming sugar]÷([Batch volume]÷355)
- Volume of table / corn sugar (cups) = [Priming sugar]÷200
Example values
How the main result changes when Target CO₂ volumes changes and everything else stays at the example values above:
| Target CO₂ volumes | Priming sugar (g) |
|---|---|
| 1.25 | 116.9 |
| 1.88 | 116.9 |
| 2.5 | 116.9 |
| 3.13 | 116.9 |
| 3.75 | 116.9 |
| 5 | 116.9 |
Formula
Residual CO₂ (volumes) = 3.0378 − 0.050062 × T + 0.00026555 × T² (T = highest temperature after fermentation, °F)
Priming sugar (g) = 15.195 × batch (US gal) × (target − residual) ÷ sugar factor
Sugar factors: table sugar 1, corn sugar 0.91, DME 0.68, honey 0.78
Worked example
Inputs — Beer style: 2.4; Batch volume: 5 US gal; Temperature unit: °F; Highest fermentation temperature: 68; Priming sugar: Table sugar (sucrose).
Results — CO₂ already in the beer = 0.86 vol; Target CO₂ = 2.4 vol; Priming sugar = 116.9 g; Per 12 oz (355 ml) bottle = 2.19 g; Volume of table / corn sugar (cups) = 0.58.
Frequently asked questions
How much priming sugar for 5 gallons?
About 100–140 g (3.5–5 oz) of corn sugar for a typical ale.
Why does fermentation temperature matter?
Cooler beer already holds more CO₂, so it needs less sugar.
Can I use regular table sugar?
Yes – use about 9% less than corn sugar.