Enter any two values—wine volume, sugar concentration (for example, g/L), or total sugar mass—into the calculator to determine the missing variable. This calculator can evaluate any one of the variables when the other two are known.

Wine Sugar Calculator

Pick a mode and enter your numbers.

Chaptalization
Brix / SG / Sugar
Potential ABV

Related Calculators

Wine Sugar Formulas

The calculator uses a different formula for each mode.

Chaptalization (sugar to add):

Sugar (g) = (gL_target - gL_current) * Volume (L)

Brix to Specific Gravity:

SG = 1 + (Brix * 0.004)

Brix to sugar (g/L):

g/L = Brix * SG * 10

Potential ABV:

ABV % = (Brix_start - Brix_final) * 0.55
  • Brix — sugar content as a percent by weight (°Bx)
  • SG — specific gravity relative to water
  • g/L — grams of sugar per liter of must
  • Volume (L) — must volume in liters (1 gal = 3.78541 L)
  • 0.55 — conversion factor for Brix consumed to ABV produced

Conversions assume sucrose in aqueous solution at 20°C. The 0.55 ABV factor is a working average; actual yield varies with yeast strain, temperature, and nutrients. The Brix to SG approximation is accurate within typical wine ranges (0–30°Bx); below that, a polynomial conversion is used internally for higher precision.

Reference Tables

Use these to sanity-check inputs and interpret results.

°Brix SG Sugar (g/L) Potential ABV
181.0721939.9%
201.08021611.0%
221.08823912.1%
241.09626313.2%
261.10428714.3%
281.11231115.4%
Wine Style Target Brix at Harvest Finished ABV
Sparkling base17–199–11%
Dry white19–2311–13%
Dry red22–2512–14%
Late harvest26–3014–16%+
Ice wine / dessert32–428–13% (high RS)

Worked Example

You have 20 liters of must at 20°Brix and want to reach 23°Brix before fermentation.

  1. Convert current: 20°Bx ≈ 216 g/L sugar.
  2. Convert target: 23°Bx ≈ 252 g/L sugar.
  3. Difference: 252 − 216 = 36 g/L.
  4. Sugar to add: 36 × 20 = 720 g (about 1.59 lb).
  5. Expected ABV gain: (23 − 20) × 0.55 ≈ 1.65%.

Why does the ABV come up short of my Brix? Yeast does not convert sugar to alcohol with 100% efficiency. The 0.55 factor accounts for cell growth, glycerol, and CO2 loss. Some strains hit 0.57; stressed fermentations can drop to 0.50.

Should I dissolve the sugar first? Yes. Dissolve cane sugar in a small amount of warm must before adding it back, then stir thoroughly. Adding dry sugar to a full vessel leads to uneven distribution.

What if my target is below my current Brix? The calculator will flag this. To lower Brix you dilute with water or blend with lower-sugar must, which is regulated or prohibited in many wine regions.