Standard Liquor Measure Sizes
A typical liquor measure, or "shot," varies by country but centers on 1-1.5 fluid ounces (30-44 ml) of 40% ABV (alcohol by volume) spirits like vodka, whiskey, or gin.
- US standard: 1.5 fl oz (44 ml) at 40% ABV contains 0.6 fl oz (17.7 ml) pure alcohol, or about 0.49 oz (14 grams) by weight. This assumes ethanol density of 0.789 g/ml.[1][2]
- UK pub measure: 1.0 fl oz (25 ml) or double 2.0 fl oz (50 ml) at 40% ABV yields 0.33 oz (9.3 g) or 0.66 oz (18.6 g) alcohol weight.[3]
- Australia/Canada: Often 1.0 fl oz (30 ml) at 40% ABV, equaling 0.39 oz (11.2 g).[4]
How Alcohol Weight Is Calculated
Multiply volume by ABV percentage, then convert to weight:
1. Pure alcohol volume = shot size (ml) × 0.40.
2. Weight (g) = that volume × 0.789.
Example for 44 ml shot: 44 × 0.40 = 17.6 ml alcohol; 17.6 × 0.789 ≈ 14 g (0.49 oz).[1][5]
Higher-proof liquors (e.g., 50% ABV) increase weight proportionally—44 ml at 50% ABV hits 0.61 oz (17.3 g).
Why Weight Matters Over Volume
Health guidelines like US Dietary Guidelines or UK's chief medical officer use grams for daily limits (e.g., 14 g "standard drink" in US equals one 1.5 oz shot).[2][3] Weight accounts for ethanol's density, aiding blood alcohol concentration estimates via Widmark formula: BAC ≈ (grams alcohol / (body weight in g × r)) × 100, where r is 0.68 for men, 0.55 for women.[6]
Variations and What Affects It
- Proof/ABV: 80-proof (40%) is baseline; rum or tequila may hit 45-50%.
- Temperature: Alcohol contracts slightly when chilled, dropping weight by 1-2%.[5]
- Serving size: Jiggers vary (1-2 oz); free pours average 1.7 oz in bars.[7]
- Country standards:
| Region | Typical Shot (ml) | Alcohol Weight (g, 40% ABV) |
|--------|-------------------|-----------------------------|
| US | 44 | 14 |
| UK | 25 | 9 |
| EU | 20-40 | 7-14 |
| Japan | 30 | 11 |[4][8]
Overpouring adds 20-30% more alcohol on average.[7]
[1] NIST Ethanol Density Tables: https://webbook.nist.gov/cgi/cbook.cgi?ID=C64175
[2] NIAAA Standard Drink Chart: https://www.niaaa.nih.gov/alcohols-effects-health/overview-alcohol-consumption/what-standard-drink
[3] UK Chief Medical Officers' Guidelines: https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/545937/UK-Chief-Medical-Officers-low-risk-drinking-guidelines.pdf
[4] WHO Global Status Report on Alcohol: https://www.who.int/publications/i/item/9789241565639
[5] TTB Alcohol Beverage Formulas: https://www.ttb.gov/images/pdfs/imprpdf/5110-1.pdf
[6] Widmark BAC Formula (Forens. Sci. Int.): https://pubmed.ncbi.nlm.nih.gov/1897385/
[7] Journal of Studies on Alcohol (pour accuracy): https://pubmed.ncbi.nlm.nih.gov/16185730/
[8] EU Spirit Drinks Regulation (EC) No 110/2008: https://eur-lex.europa.eu/legal-content/EN/TXT/?uri=CELEX:32008R0110