Our Brix to ABV Calculator converts your refractometer or hydrometer Brix readings into estimated alcohol by volume — perfect for winemakers and cider makers who measure sugar in Brix instead of specific gravity.
Brix to ABV Calculator
Brix to ABV Formula
ABV (%) = (Starting Brix − Final Brix) × 0.55
This is the standard quick-estimate formula used by home winemakers and cider makers. It works well for most dry to semi-dry wines/ciders. Note that final Brix readings can go negative (e.g. −1 to −3°Bx) once fermentation finishes, because alcohol has a lower density than water and skews the refractometer/hydrometer reading.
Why Use Brix Instead of Specific Gravity?
Winemakers and orchard/vineyard growers commonly measure sugar content in Brix (using a refractometer) because it directly estimates potential sugar content in grapes or fruit before pressing. Brewers more often use specific gravity (SG) with a hydrometer. Both measure the same underlying thing — dissolved sugar concentration — just on different scales.
Brix to Specific Gravity Conversion Reference
| Brix (°Bx) | Specific Gravity | Approx. Potential ABV |
|---|---|---|
| 18 | 1.074 | ~10.6% |
| 20 | 1.083 | ~11.8% |
| 22 | 1.091 | ~13.0% |
| 24 | 1.099 | ~14.2% |
| 26 | 1.108 | ~15.4% |
Tips for Accurate Brix Readings
- Don’t use a standard refractometer once fermentation has started. Alcohol skews refractometer readings — for accurate final readings, use a hydrometer instead, or use a refractometer correction formula/calculator.
- Temperature-correct your readings. Most refractometers are calibrated at 20°C (68°F) — readings taken at very different temperatures need correction.
- Take the starting Brix before adding any water or sugar adjustments so your ABV estimate reflects the actual must/juice that fermented.
FAQs
Can my final Brix reading be negative?
Yes — this is normal. Alcohol is less dense than water/sugar solution, so a refractometer or hydrometer reading after fermentation often reads below zero on the Brix scale.
Is the 0.55 multiplier always accurate?
It’s a reliable approximation for most wine and cider fermentations, typically within 0.2-0.5% of lab-tested results. For more precision, convert Brix to specific gravity and use the SG-based ABV formula (SG difference × 131.25).
What’s a typical starting Brix for wine grapes?
Most wine grapes are harvested between 20-26°Bx, corresponding to roughly 11-15% potential alcohol depending on the style being made.
Do I need a refractometer or hydrometer for this calculator?
Either works for the starting reading. For the final reading, a hydrometer is more reliable since alcohol distorts refractometer readings.