Calculate how much sulfite to stir into a carboy so the wine hits the SO₂ dose you meant.
| SO₂ (mg) | – |
| K-metabisulfite | – |
Use this wine SO₂ calculator for home winemaking when adding Campden or potassium metabisulfite at a target parts-per-million. It is not for sulphuring crops.
ppm is milligrams per litre, so SO₂ milligrams = litres × ppm. Potassium metabisulfite is treated as about 57% SO₂ by mass, so grams of K-meta are SO₂ milligrams ÷ 0.57 ÷ 1000. Free versus bound SO₂ is not modelled. Wine volume can be litres or gallons.
Wine: Wine in the vessel. 20 L is a typical carboy; a 750 ml bottle is 0.75 L.
Target SO₂ (ppm): Target SO₂ in milligrams per litre. 50 ppm is a common addition at racking; follow a chart for your pH.
SO₂ (mg): Milligrams of SO₂ that dose represents.
K-metabisulfite: Mass of potassium metabisulfite to weigh.
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