Priming Sugar Calculator
Calculate how much sugar to add when bottling beer to reach your target carbonation.
Last updated · View algorithm, constants and default inputs (JSON)
About this calculator
Beer already holds dissolved carbon dioxide from fermentation, and how much depends on the temperature it was stored at. Priming sugar only needs to make up the difference to your target.
Worked example
calculated with the default values below
Batch volume 20 L · Target CO₂ volumes 2.4 vol · Beer temperature at bottling 20 °C · Priming sugar Corn sugar (dextrose) Priming sugar 115.5 g · Sugar per litre 5.78 g/L · Residual CO₂ from fermentation 0.88 vol · Approximate cups 0.578 cups
General background references
Disclaimer
These calculators give general cooking guidance. Ingredient density, oven calibration, altitude and equipment all vary, and safe minimum internal temperatures always take precedence over timings. Follow the food-safety advice issued by your national authority.
Implementation source
This record describes the implementation used by this page. It is not independent validation. External references, when available, support only the stated formula or definition; estimates and custom rules retain their own assumptions.
Formula and variables
m = V × max(T − r(t), 0) × F_i, i ∈ {1,2,3,4}; F₁ = 3.8; F₂ = 3.6; F₃ = 4.9; F₄ = 5.3
- V
- Beer volume (L)
- T
- Target CO₂ (volumes)
- r(t)
- Residual CO₂ at temperature t
- i
- Sugar type index
- F_i
- Factor for sugar type i
- m
- Priming sugar (g)
r(t) is a 36-entry lookup for 0–35 °C (1.70 down to 0.56), index clamped. F₁ corn sugar = 3.8, F₂ table sugar = 3.6, F₃ DME = 4.9, F₄ honey = 5.3. Cups = m ÷ 200; sugar per litre = max(T − r, 0) × F_i.
Frequently asked questions
Why does colder beer need less priming sugar at bottling?
Residual dissolved CO2 from fermentation falls as temperature rises, so a warm batch already holds less and the calculator must add more sugar to reach your target. At 20C the chart shows about 0.91 volumes still in solution; near 0C about 1.70 volumes remain. For a 2.4-volume target, the warm batch needs sugar for 1.49 volumes while the cold one needs only 0.70.