# Standard drink

United States standard drinks of beer, malt liquor, wine, and spirits compared. Each contains about 14 grams or 17.7 ml of ethanol.

A standard drink is a measure of alcohol consumption representing a hypothetical beverage which contains a fixed amount of pure alcohol. A standard drink varies in volume depending on the alcohol concentration of the beverage (for example, a standard drink of spirits takes up much less space than a standard drink of beer), but it always contains the same amount of alcohol and therefore produces the same amount of drunkenness.

The standard drink is used in relation to recommendations about alcohol consumption and its relative risks to health. Many government health guidelines specify low to high risk amounts in units of grams of pure alcohol per day, week, or single occasion. The concept of the standard drink is meant to help visualize and estimate the absolute alcohol content of various drink concentrations and serving sizes.

Labeling is usually required to give an indication of alcoholic content of a serving.

## Definitions in various countries

The standard drink or standard unit aims at comparing the pure ethanol regardless of the type of beverage.[1] It helps to educate alcohol users.[1] These are the amounts of alcohol defined by several countries for standardising measurement of drinking levels and providing public health information.

Different countries define standard drinks differently. For example, Australia, a standard drink contains 10 grams of alcohol,[2] but in Japan, one "unit" contains approximately 20 grams.[3] In addition, a standard drink is often different from normal serving size in the country in which it is served.[4]

The term "standard drink" was used in the United Kingdom in the first guidelines (1984) that published "safe limits" for drinking, but this was replaced by reference to units of alcohol in the 1987 guidelines and that term has been used in all subsequent UK guidance.[5] A unit of alcohol is defined there as 10 millilitres (8 grams) of pure alcohol.[6][7] This definition is independent of the strength (% ABV) and amount (volume) of any individual alcoholic beverage. The number of units of alcohol in a bottle or can (and, optionally, the number of units in a typical serving) are indicated on the drink container. Typical servings deliver 1–3 units of alcohol.[8]

In the United States, a standard drink is defined as 0.6 US fluid ounce of ethanol per serving, which is about 14 grams of alcohol.[9][10][11] This corresponds to a 12-US-fluid-ounce (350 mL) can of 5% beer, a 5-US-fluid-ounce (150 mL) glass of 12% ABV (alcohol by volume) wine, or a 1.5-US-fluid-ounce (44 mL) so-called "shot" of spirit,[9] assuming that beer is 5% ABV, wine is 12% ABV, and spirits is 40% ABV (80 proof).

${\displaystyle {\frac {0.6\,\mathrm {fl\,oz} \ {\text{(ethanol)}}}{5\%\,\mathrm {ABV} \ {\text{(beer)}}}}={\frac {\left({\tfrac {3}{5}}\right)}{\left({\tfrac {1}{20}}\right)}}={\frac {60}{5}}=12\ \mathrm {fl\,oz} \ {\text{(serving)}},}$
${\displaystyle {\frac {0.6\,\mathrm {fl\,oz} \ {\text{(ethanol)}}}{12\%\,\mathrm {ABV} \ {\text{(wine)}}}}=5\,\mathrm {fl\,oz} \ {\text{(serving)}},}$
${\displaystyle {\frac {0.6\,\mathrm {fl\,oz} \ {\text{(ethanol)}}}{40\%\,\mathrm {ABV} \ {\text{(spirit)}}}}=1.5\,\mathrm {fl\,oz} \ {\text{(serving)}}}$

Most wine today is higher than 12% ABV (the average ABV in Napa Valley in 1971 was 12.5% [12]). 80 proof is still the standard for spirits, though higher alcohol content is common.

There is no international consensus on how much pure alcohol is contained in a standard unit.[13] Some choose to base the definition on mass of alcohol (in grams) while others base the unit on the volume (in mL or other volume units). This makes different quantities for a "standard" drink/unit in different countries depending on local customs and beverage packaging.[1]

For comparison, both measurements are shown here. There is no single standard, but a standard drink of 10 g alcohol, which is used in the WHO AUDIT (Alcohol Use Disorders Identification Test)'s questionnaire form example,[14] have been adopted by more countries than any other amount.[15] The terminology for the unit also varies, as shown in the Notes column.

Within the European Union, the most frequent value is 10 g of pure ethanol, followed by 12 g, but units vary from 8 to 20 g.[16][17]

Country Mass (g) Volume (mL) Notes
Australia[15][18] 10 12.7
Austria[15][19] 20 25.3
Canada[15][20][21] 13.6 or 13.45 [22] or 13.5[23] 17.2 or 17 [22] This specific unit is computed based on the oz definition as:
• 12 oz (341 ml) bottle of 5% alcohol beer, cider or cooler
• 1.5 oz (43 ml) shot of 40% hard liquor (vodka, rum, whisky, gin etc.)
• 5 oz (142 ml) glass of 12% wine.[24]
Denmark[15][19] 12 15.2
Finland[25] 12 15.2
France[15] 10 12.7
Germany[15][26] 11 13.8 Standardglas defined as containing 10–12 g (central value used here)
Hong Kong[27] 10 12.7
Hungary 17 21.5
Iceland[15][28] 8 10 áfengiseining defined as 8 g but treated as equivalent to 10 mL
Ireland[15][29] 10 12.7
Italy[15] 10 12.7 unità standard defined as 10 mL
Japan[14][3] 19.75 25 "unit (tan'i)". MHLW's conventional unit, based on 1 gō (unit)(approx. 180 mL) of sake. Not any "standard".
Japan[3] 10 12.7 "drink (dorinku)". Introduced around 2011 to align with the WHO AUDIT, and to avoid the conventional unit (20 g) of giving a false impression of "minimum amount to drink".[30] Sometimes also called "unit (tan'i)".[31] Has no implication of being any "standard".
Netherlands[19] 10 12.7
New Zealand[15][32][33] 10 12.7
Norway 12.8 15
Poland[15] 10 12.7
Portugal[15] 11 13.8 10–12 g (central value used here)
Spain[15] 10 12.7
Sweden[34] 12 15.2 standardglas corresponds to 33 cl 5% beer, 13 cl wine, or a drink or shot based on 4 cl 40% liquor
Switzerland[15] 12 15.2
United Kingdom[15][35] 8 10 unit of alcohol defined as 10 mL but treated as equivalent to 8 g
United States[9][15][36] 14 17.7 standard drink defined as 0.6 fl oz (US) or 14 g

## Calculation of pure alcohol mass in a serving

Pure alcohol mass in a serving can be calculated if concentration, density and volume are known.

${\displaystyle {\text{Pure alcohol mass}}={\text{volume}}\times {\text{alcohol by volume}}\times {\text{volumetric mass density}}}$

For example, a 350 ml glass of beer with an ABV of 5.5% contains 19.25 ml of pure alcohol, which has a density of 0.78945 g/mL (at 20 °C),[11] and therefore a mass of 15.20 grams.

${\displaystyle 350\,\mathrm {mL} \times 0.055\times 0.78945\,\mathrm {g} /\mathrm {mL} \approx 15.20\,\mathrm {g} }$
or
${\displaystyle 0.35\,\mathrm {L} \times 0.055\times 789.45\,\mathrm {g} /\mathrm {L} \approx 15.20\,\mathrm {g} }$

When drink size is in fluid ounces (which differ between the UK and the US), the following conversions can be used:

Country Volume of fl. oz. (mL) Mass of fl. oz. of alcohol (g)
UK 28.41 22.43
US 29.57 23.34

One should bear in mind that a pint in the UK is 20 imperial fluid ounces, whereas a pint in the US is 16 US fluid ounces. However, as 1 imperial fl. oz. ≈ 0.961 US fl. oz., this means 1 imperial pint ≈ 1.201 US pints (i.e. 0.961 × 20/16) instead of 1.25 US pints.

Standard drink chart (U.S.)[37]
Alcohol Amount (ml) Amount (fl oz) Serving size Alcohol (% by vol.) Alcohol
80 proof liquor 44 1.5 One shot 40 0.6 US fl oz (18 ml)
Table wine 148 5 One glass 12 0.6 US fl oz (18 ml)
Beer 355 12 One can/bottle 5 0.6 US fl oz (18 ml)

Standard drink sizes (Australia)

• 375 ml can of light beer (2.7% alcohol) = 0.8 standard drinks
• 375 ml can of mid-strength beer (3.5% alcohol) = 1 standard drink
• 375 ml can of full strength beer (4.8% alcohol) = 1.4 standard drinks
• 100 ml glass of wine (13.5% alcohol) = 1 standard drink
• 150 ml glass of wine (13.5% alcohol) = 1.5 standard drinks
• 30 ml shot of spirits (40% alcohol) = 0.95 standard drinks
• 440 ml can of pre-mix spirits (approx. 5% alcohol) = 1.7 standard drinks
• 440 ml can pre-mix spirits (approx. 7% alcohol) = 2.4 standard drinks

## Relation to blood alcohol content

As a rough guide, it takes about one hour for the body to metabolize (break down) one UK unit of alcohol, 10 ml (8 grams). However, this can vary with body weight, sex, age, personal metabolic rate, recent food intake, the type and strength of the alcohol, and medications taken. Alcohol may be metabolized more slowly if liver function is impaired.[8] As a rule of thumb of the time to metabolize, multiply one hour by the number of alcohol units in the local definition of a standard drink. For example, in the United States one standard drink contains 14 grams ≈ 1.75 units of alcohol, and so takes the body about an hour and three-quarters to process.

Blood alcohol content can more accurately be estimated by a method developed by Swedish professor Erik Widmark [sv] in the 1920s:[38]

${\displaystyle EBAC=({\frac {A}{r\times Wt}}\times 100\%)-(\beta \times T)}$

where:

• A is the mass of alcohol consumed.
• r is the ratio of body water to total weight. It varies between individuals but averages about 0.68 for men and 0.55 for women, since women tend to have a higher percentage of fat.
• Wt is body weight.
• β is the rate at which alcohol is metabolized. It is approximately 0.017% per hour.
• T is the amount time during which alcohol was present in the blood (usually time since consumption began).

Regarding metabolism (β) in the formula; females demonstrated a higher average rate of elimination (mean, 0.017; range, 0.014–0.021 g/210 L) than males (mean, 0.015; range, 0.013–0.017 g/210 L).

Examples:

• 80 kg male drinking 2 drinks of 14 grams (0.014 kg) each, in two hours:
${\displaystyle EBAC=(2\times 0.014)/(0.68\cdot 80)\times 100\%-(0.015\cdot 2)\approx 0.021\%}$
• 70 kg woman drinking 1.5 drinks of 14 grams each, in two hours:
${\displaystyle EBAC=(1.5\times 0.014)/(0.55\cdot 70)\times 100\%-(0.017\cdot 2)\approx 0.021\%}$

## Labeling

Labeling is usually required to give an indication of alcoholic content of a serving. Australia requires that "the label on a package of an alcoholic beverage must include a statement of the number of standard drinks in the package".[2]

Research in the UK has shown that including pictures of units and a statement of the drinking guidelines could help people understand the recommended limits better.[39][40]

## References

1. ^ a b c "Health Promotion Knowledge Gateway".
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3. ^ a b c "AUDIT The Alcohol Use Disorders Identification Test (Second Edition)" アルコール使用障害特定テスト使用マニュアル (pdf). WHO (in Japanese). p. 17. Retrieved 2020-01-02.
4. ^ Mongan, Deirdre; Long, Jean (May 22, 2015). "Standard drink measures throughout Europe; peoples' understanding of standard drinks and their use in drinking guidelines, alcohol surveys and labelling" (PDF). Reducing Alcohol Related Harm. p. 8. Retrieved September 26, 2017.
5. ^ "Alcohol guidelines, Eleventh Report of Session 2010–12" (PDF). UK Parliament. House of Commons, Science and Technology Committee. 7 December 2011. p. 7. Retrieved 13 February 2015.
6. ^
7. ^ "How long does alcohol stay in your blood?". NHS Choices. Retrieved 11 February 2015.
8. ^ a b "The risks of drinking too much". nhs.uk. October 3, 2018.
9. ^ a b c rethinkingdrinking.niaaa.nih.gov, US NIH Web site:What's a "standard" drink?
10. ^ 14 grams of alcohol is 0.6 US fluid ounces or ~18 mL. → Ethanol listed as 0.78945 g/mL @ 20°C (68°F), 0.6 US fl oz × 29.57 mL/US fl oz = 17.742 ml; 0.78945 g/mL × 17.742 mL = 14.006g
11. ^ a b Haynes, William M., ed. (2011). CRC Handbook of Chemistry and Physics (92nd ed.). Boca Raton, FL: CRC Press. p. 3.246. ISBN 1-4398-5511-0.
12. ^
13. ^ Furtwaengler, Nina A. F. F.; De Visser, Richard O. (2013). "Lack of international consensus in low-risk drinking guidelines". Drug and Alcohol Review. 32 (1): 11–18. doi:10.1111/j.1465-3362.2012.00475.x. PMID 22672631.
14. ^ a b "AUDIT The Alcohol Use Disorders Identification Test (Second Edition)" (pdf). WHO. 2001. Retrieved 2020-01-02.
15. Kalinowski, A.; Humphreys, K. (2016-04-13). "Governmental standard drink definitions and low‐risk alcohol consumption guidelines in 37 countries". Addiction. 111 (7): 1293–8. doi:10.1111/add.13341. PMID 27073140.
16. ^
17. ^
18. ^ Population Health Division, Australian Government Department of Health and Ageing The Australian Standard Drink Archived 2019-05-30 at the Wayback Machine
19. ^ a b c "Drinking Guidelines: General Population". IARD.org. International Alliance for Responsible Drinking. Retrieved 23 June 2016.
20. ^ Canadian Public Health Association. URL: [1]. 2006.
21. ^ Centre for Addiction and Mental Health / Centre de toxicomanie et de santé mentale Low-Risk Drinking Guidelines
22. ^ a b Canada, Health (May 17, 2013). "Alcohol use". www.canada.ca.
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24. ^
25. ^ paihdelinkki.fi, How to use alcohol wisely
26. ^ "Was ist ein Standardglas?" [What is a standard drink?]. Alkohol? Kenn dein Limit. (in German). Bundeszentrale für gesundheitliche Aufklärung. Retrieved September 26, 2017.
27. ^ Department of Health Alcohol and Health: Hong Kong Situation
28. ^ "Landlæknisembættið, Icelandic Directorate of Health" (PDF). Archived from the original (PDF) on 2022-07-10. Retrieved 2017-09-25.
29. ^ Hope, A. (2009). A Standard Drink in Ireland: What strength? (PDF). Health Service Executive. Retrieved 2 February 2015.
30. ^ "Units of alcoholic drink" 飲酒量の単位. Japan MHLW e-healthnet (in Japanese). Retrieved 2020-01-02.
31. ^ MHLW. "tips on alcohol use control consultation – Core-AUDIT" アルコール指導のポイント Core-AUDITの章 (PDF). Japan National Institute of Public Health (in Japanese). p. 48. Retrieved 2020-01-02.
32. ^ New Zealand Food Safety Authority Archived 2008-07-04 at the Wayback Machine
33. ^ Alcohol Advisory Council of New Zealand (ALAC) What's in a Standard Drink
34. ^ "Vad är ett standardglas alkohol? | alkoholhjälpen.se". alkoholhjalpen.se.
35. ^ PRODIGY Knowledge (Department of Health) Alcohol and Sensible Drinking Archived 2006-09-25 at the Wayback Machine
36. ^ "Alcohol and Public Health: Frequently Asked Questions". CDC. Retrieved 2011-10-17.
37. ^ Based on the CDC standard of 0.6 fl oz alcohol per drink. CDC alcohol FAQ
38. ^ Ed Kuwatch. "Fast Eddie's 8/10 Method of Hand Calculating Blood Alcohol Concentration: A Simple Method For Using Widmark's Formula". Archived from the original on 2003-12-02.
39. ^ "Drinks labels with pictures and guidelines could improve public understanding of Government recommendations". NIHR Evidence (Plain English summary). 2021-06-23. doi:10.3310/alert_46590. S2CID 242903619.
40. ^ Gold, Natalie; Egan, Mark; Londakova, Kristina; Mottershaw, Abigail; Harper, Hugo; Burton, Robyn; Henn, Clive; Smolar, Maria; Walmsley, Matthew; Arambepola, Rohan; Watson, Robin (19 January 2021). "Effect of alcohol label designs with different pictorial representations of alcohol content and health warnings on knowledge and understanding of low‐risk drinking guidelines: a randomized controlled trial". Addiction. 116 (6): 1443–1459. doi:10.1111/add.15327. ISSN 0965-2140. PMC 8248341. PMID 33169443.