How strong is a cocktail?
The strength of a mixed drink depends on three things: how much of each ingredient goes in, how strong each one is, and how much water the ice adds. That last point is often forgotten, yet shaking a cocktail with ice typically adds a quarter of its volume in water, which brings a drink of straight spirits and liqueurs down by several points.
The formula
- Pure alcohol = Σ (volume of each ingredient × its ABV)
- Total volume = sum of the ingredients × (1 + dilution)
- ABV = pure alcohol ÷ total volume
The calculator then converts the pure alcohol into grams (1 mL of ethanol weighs 0.789 g) and into US standard drinks of 14 g. It also shows the strength before dilution and the proof, which in the US is twice the ABV.
Typical dilution
| Method | Water added |
|---|---|
| No ice (neat, or chilled bottle) | 0% |
| Built over ice | about 10% at first, more as it sits |
| Stirred with ice | about 20% |
| Shaken with ice | about 25% |
These are averages: small ice, long shaking and a warm kitchen all add water.
Worked example: a margarita
- 2 oz tequila at 40%
- 1 oz triple sec at 40%
- 1 oz fresh lime juice at 0%
- Shaken with ice (+25%)
Pure alcohol = 2 × 0.40 + 1 × 0.40 = 1.2 oz (35.5 mL). The 4 oz of ingredients become 5 oz after shaking. ABV = 1.2 ÷ 5 = 24%, compared with 30% before dilution. The drink holds about 28 g of alcohol, or 2.0 standard drinks.
Typical strengths
| Drink | Approximate ABV |
|---|---|
| Martini, Manhattan (stirred) | 25–32% |
| Margarita, daiquiri (shaken) | 18–24% |
| Old fashioned (over ice) | 30–35% |
| Highball such as gin and tonic | 8–12% |
| Aperol spritz | 8–9% |
Drinking responsibly
A cocktail often contains two standard drinks or more, which matters for the US guidance to keep daily intake low and for blood alcohol before driving. Bartenders’ recipes are also getting stronger with larger pours, so check your own measures rather than counting “one drink” per glass.