Skip to content
Docs · Tools

Brix to potential alcohol calculator

Estimate a wine must's potential alcohol from its Brix or specific gravity reading, using the 0.55–0.59 winemaking convention — an estimate, not an official measurement.

The Brix to Potential Alcohol calculator estimates the potential alcohol of a wine must — the ABV it would reach if the sugar ferments to dryness — from a Brix or specific-gravity reading of the must.

It's an estimate, using a winemaking rule of thumb with no government formula behind it, and never valid for a tax or label filing. On the hub it sits in the Estimates (non-regulatory) section, and the calculator opens with a Non-regulatory estimate badge and a highlighted note.

It's free, needs no account, and computes in your browser.

Open the calculator

  • On the public site: in the top navigation choose Tools, then — in the Estimates (non-regulatory) section — on the Brix to Potential Alcohol card choose Open calculator.
  • Inside the app: in the navigation choose Tools, then on the Brix to Potential Alcohol card choose Open calculator.

Choose a conversion factor

Under Conversion factor you can pick the multiplier used for the estimate:

  • × 0.59 (ferments to dryness) — the default. Assumes nearly all the sugar ferments out — the higher estimate.
  • × 0.55 (conservative) — allows for non-sugar solids that never ferment — the lower estimate.

The two factors bracket the likely result. The calculator starts on × 0.59.

Estimate the potential alcohol

  1. In Must sugar reading, enter your refractometer or hydrometer reading.
  2. From Reading unit, choose °Brix (the default) or Specific gravity. A small hint under the field shows the reading converted to the other unit (for example, a Brix reading shows its approximate specific gravity). A Brix reading must be between 0 and 40; a specific gravity between 0.98 and 1.2.
  3. Under Conversion factor, leave × 0.59 selected or choose × 0.55.
  4. Potential alcohol, shown as a percentage of ABV and labelled with the factor in use, appears as soon as the reading is valid.

If the reading is out of range, the field shows a hint (Enter a Brix reading between 0 and 40. or Enter a specific gravity between 0.98 and 1.2.). Above roughly 30 °Brix the calculator warns that many yeasts stall, so the real alcohol may fall short of the estimate if the fermentation sticks.

Worked example

A must reading 24 °Brix, on the default × 0.59 factor:

  1. Must sugar reading: 24
  2. Reading unit: °Brix
  3. Conversion factor: × 0.59 (ferments to dryness)

The calculator shows Potential alcohol (× 0.59 (ferments to dryness)) 14.16% ABV.

When to reach for it

Reach for Brix to Potential Alcohol when you're checking a must before fermentation and want to know roughly how strong the wine could finish. It's a rule of thumb — the actual alcohol depends on how far the yeast takes the ferment — and the number that governs any filing comes from a real measurement, not this estimate. A note at the bottom of the calculator restates this, and the page-bottom disclaimer confirms it's a reference tool, never a system of record for a filing.