Priming Sugar Calculator — Batch & Bottle Solution Doses
Plan priming sugar for beer or measured sugar-solution doses for mixed bottle sizes. Account for residual CO2, final solution volume and dilution.
Plan sugar for fully fermented beer, or dose a measured sugar solution into mixed bottle sizes.
Beer in each bottle, before the dose
Leave room for the added solution and suitable headspace. These are fill amounts, not nominal bottle capacities.
Residual CO₂ and model assumptions
The temperature model supports 0–30 °C. It does not measure actual dissolved gas. For spunded beer, use a measured residual value.
Priming sugar & bottle dosing plan
Weigh table sugar
126.24 gFor 20 L of beer · target 2.5 volumes CO₂
- Residual CO₂ estimate
- 0.861 volumes
- Sugar per litre of beer
- 6.31 g
- Added CO₂ needed
- 1.639 volumes
Batch result treats the beer volume as fixed. If adding a sizeable volume of liquid, use the prepared-solution mode to account for dilution.
Gas-yield model · table sugar yields 0.51 g CO₂/g. Residual 0.861 volumes, estimated at 20 °C. Actual carbonation depends on fermentation, gas losses and headspace.
Before bottling: confirm fermentation is complete and use packages rated for your intended carbonation. This tool does not assess package strength, spoilage or remaining fermentable sugar.
Calculation and sources
The model converts required CO₂ at standard conditions to sugar mass, using 44.01 / 22.4 g CO₂ per litre of gas and sugar yields of 0.51 (sucrose), 0.44 (dextrose monohydrate) or 0.49 (anhydrous glucose). These are approximate planning coefficients, not batch measurements. The result can differ from calculators using the practical 4 g sucrose per litre per added CO₂ volume.
For a prepared solution, the dose accounts for its added liquid volume and assumes the solution contains no CO₂. Beer and solution volumes are treated as additive. No compensation for headspace or packaging gas loss is added. A very dilute solution may not be able to reach the target.
Sources: Top-Down Brew model documentation, Brewer’s Friend residual CO₂ model, Brewers Association package guidance.
