Hong Life CalculatorsUnderstanding the cocktail ABV calculator — concept and principle
How strong is the drink in your glass? A cocktail mixes spirits, liqueurs and non-alcoholic ingredients, and shaking or stirring with ice adds meltwater. This calculator combines the alcohol from every ingredient, accounts for dilution and reports the final alcohol by volume (ABV), the finished volume and the number of 10-gram standard drinks. It also works for infused spirits, punches and batch cocktails.
How it is calculated
- Pure alcohol (mL) = Σ (volume × ABV ÷ 100) for each ingredient.
- Final volume = Σ volumes × (1 + dilution ÷ 100).
- Final ABV = Σ (volume × ABV) ÷ final volume.
- Standard drinks = pure alcohol (mL) × 0.789 g/mL ÷ 10 g.
Enter volumes and ABVs as comma-separated lists in the same order; non-alcoholic ingredients have ABV 0.
The principle
ABV is a volume fraction: millilitres of ethanol per 100 mL of drink. Mixing does not create or destroy alcohol, so the total ethanol is the sum of each ingredient's share, and the concentration falls as the volume grows. Melted ice is pure water and adds volume only. Ethanol's density of about 0.789 g/mL converts volume to grams, the unit used for standard drinks. Strictly, ethanol and water contract slightly when mixed, but the effect on a cocktail is small.
Worked example
Defaults: 50 mL at 40 %, 25 mL at 20 %, 100 mL at 0 %, 20 % dilution.
- Pure alcohol = 50 × 0.40 + 25 × 0.20 = 20 + 5 = 25 mL.
- Undiluted volume = 175 mL; with 20 % dilution: 175 × 1.2 = 210 mL.
- ABV = 25 ÷ 210 = 11.9 %.
- Ethanol mass = 25 × 0.789 = 19.725 g, so 19.725 ÷ 10 = 1.97 standard drinks.
| Dilution from ice (%) | Final ABV |
|---|---|
| 5 | 13.61% |
| 10 | 12.99% |
| 15 | 12.42% |
| 20 | 11.9% |
| 25 | 11.43% |
| 30 | 10.99% |
| 40 | 10.2% |
How to read the result
Many spirit-forward stirred cocktails end up in the high 20s to around 30 % ABV, while long drinks with lots of mixer are often under 10 %. The standard-drink count matters more for your body than ABV alone: a large weak drink can contain as much alcohol as a small strong one. Definitions differ by country: 10 g is used by the WHO and in Australia, a US standard drink is 14 g and a UK unit is 8 g.
Common mistakes
- Entering lists of different lengths; the calculator then cannot pair volumes with ABVs.
- Using proof instead of ABV (US proof is twice the ABV).
- Applying shaken-drink dilution to a drink built over ice and served without shaking.
Frequently asked questions
How much does shaking dilute a drink?
Shaken drinks typically gain roughly 20–25 % water; stirred drinks usually a bit less.
How strong is a spirit infused with fruit?
Enter the fruit's absorbed juice as a 0 % ingredient; the alcohol is spread over more liquid.
Does sugar syrup change ABV?
Only through its volume, as an ingredient with 0 % ABV.
Sources: World Health Organization — AUDIT: The Alcohol Use Disorders Identification Test (standard drink of 10 g). · Dave Arnold, Liquid Intelligence: The Art and Science of the Perfect Cocktail (W. W. Norton).