The Wine Potential ABV Calculator tells you how strong a wine your must can produce. Enter the Brix or specific gravity of the unfermented juice and it returns the potential alcohol if fermented dry — essential for planning chaptalization or a sweeter, arrested-fermentation style.
How it works
There are two equivalent routes.
From Brix. Winemakers use a simple conversion factor:
potential ABV ≈ Brix × 0.57
The factor varies in references between about 0.55 and 0.59; this tool uses 0.57 as a representative middle value. A 24 Brix must therefore has a potential of about 13.7% ABV.
From specific gravity. Potential alcohol is the gravity drop to a dry finish times 131.25. Wine ferments very dry, so the tool assumes a finishing gravity of about 0.992 unless you specify otherwise:
potential ABV ≈ (OG − FG_dry) × 131.25
If you enter Brix, it is first converted to gravity with the standard relationship before this step, so both routes agree.
Worked example
A red-grape must reads 24 Brix (about 1.101 SG). The Brix route gives 24 × 0.57 ≈ 13.7% potential ABV. Fermented to a dry 0.992, the gravity route gives (1.101 − 0.992) × 131.25 ≈ 14.3% — the small difference reflects the factor range, and either is a sound planning figure.
Sweeter styles and chaptalization
- To make a sweeter wine, enter a target final gravity above the dry point. The tool shows the lower ABV you reach and the residual sugar left behind.
- If the potential ABV is below your target, your must needs chaptalization — add sugar to raise the Brix until the potential reaches your goal.
- Stopping fermentation early to retain sweetness requires chilling, racking off the lees, and stabilising with sorbate and sulphite.