There are lots of benefits associated with alcohol. But you can only get these benefits if you know the right quantity of alcohol to drink per week or per day. This can be achieved if you know the different ways in which alcoholic content is measured or expressed. The alcoholic content in a drink can be expressed in different units. Units used to express alcoholic content includes alcohol by volume (ABV), unit (or alcohol unit), standard drink and pint (or alcohol pint). Each unit represents a measure of the amount of alcohol in your drink.
The aim of expressing alcoholic content in different units is to provide consistency across different beverage types, to provide drinking guidelines and advice, and to interpret the science behind drinking and health into a message that can be understood.

ABV measurements

ABV (alcohol by volume) is a measure of the percentage (%) of pure alcohol in a given volume of drink. For example, a 500 mL alcoholic drinks which reads “5 % ABV”, “5.0% ALC/VOL” or “alcohol volume 5 %” implies 5 % of the total volume of that drink is pure alcohol. In our case, 5 % of 500 mL will give us 25 mL. This means 25 mL of 500 mL is pure alcohol calculated as:

[(5/100) X 500 mL]

ALCOHOL AS A UNIT

Alcohol content can also be expressed in terms of unit. A unit of alcohol estimates the amount of pure alcohol in a drink and gives an idea of how strong a drink is. One unit of alcohol is equals to 8.0 g or 10 mL of pure alcohol.
The number of units in a drink depends on its size and strength. To calculate the number of units in a drink, simply multiply the size of the bottle and the strength of the alcohol and then divide this by 1000 as shown below:

Percentage of alcohol  X Volume of alcohol (mL) ÷ 1000 = Units

For example a 440 mL of a 5 % alcohol will be 5 X 440 ÷ 1000 = 2.2 units.

In an adult, it takes about 1 hour for your liver to breakdown or process one unit of alcohol. Time taken to completely break down 1 unit of alcohol will be affected by your weight, gender, age, rate of metabolism, how empty your stomach is, the type of alcohol you drank and any medication you might be taking.
One of the major aim of expressing alcohol as a unit is to help people keep track of their drinking. Generally, it is recommended not to drink more than 2 to 3 units per day or more than 14 units of alcohol per week.

MEASURING ALCOHOL AS A STANDARD DRINK

According to the national institute of health (NIH), a standard drink also called an alcoholic drink-equivalent is any drink which contains about 0.60 fluid ounce (fl oz) or 14 grams (g) of pure alcohol. It is calculated based on the percentage of alcohol and its volume. The fomulars below can be used depending on whether your alcohol volume is in mL or fl oz. 

1 standard drink = Volume (fl oz) X ABV content (%) ÷ 100  

                        OR

1 standard drink = Volume (mL) X ABV alcohol (%) ÷1774.41

Example 1:  A 12 fl oz of a 5 % alcohol will be 0.6 fl oz (or 1 drink) calculated as “12 fl oz X 5 ÷100”.

Example 2: A 750 mL of a 12 % alcohol will be 5 drinks calculated as “750 mL X 12 ÷ 1774.41”.

The definition of a standard drink unlike a unit of alcohol varies across countries.

  • A standard drink in the UK,contains 8 g of pure alcohol
  • In Australia and France,a standard drink is 10 g of pure alcohol
  • A Mexican standard drink contains 13 g of pure alcohol
  •  In USA, Argentina and Chile a standard drink is 14 g of pure alcohol

 DRINKING CATEGORIES

A consumer of alcoholic beverages can be classified as a light, moderate, high or heavy drinker. According to the Journal of Clinical Nutrition: 

  • Light alcohol drinking equals 0.1-7 drinks per week
  • Moderate alcohol drinking equals 7.1-14 drinks per week
  • High alcohol drinking equals 14.1-28 drinks per week
  • Heavy alcohol drinking is > 28 drinks per week 
  • Light drinking is also when you drink less than 100 g of pure alcohol per week or less than 14 units of alcohol per week.

ALCOHOL PINT

A pint of alcohol  is a unit which measures the volume of alcohol you drink.  A pint of alcoholic drink varies based your location. In the UK, Ireland and other commonwealth nations, a pint of alcohol equals 568 mL. In other parts of Europe such as Germany and Swizerland, 1 pint equals 500 mL while in the US a pint vary significantly. Most common is the US liquid pint of about 473 ml and the less frequently used US dry pint of about 551 mL. Traditionally in the US, a pint can also mean 375 mL and a half pint 200 mL. 

A pint says nothing about the strenght of an alcoholic drink. Therefore, the percentage of alcohol in a pint will depend on the volume and percentage of alcohol you are having. 

Note: 1 US fluid ounce (fl oz) equals 29.5735 mL and 1 L equals 1000 mL.

Drinks and units

The table below provides a guide for the number of alcohol units in different drinks. This serves to help guide you in controlling your drinking habit.
Determining the number of units is based on the strength (ABV %) and the volume of alcohol. So, even if your favorite drink is not listed but have same strength and volume as any of the listed drinks below, then consider the number of alcohol units to be the same. Secondly, if a smaller volume with a given strength is listed and you need for a larger volume, then simply do some multiplications. For example, if you need the number of units in 750 mL of 12.0 % wine, then simply multiply 3 X 3 to get 9 units. This is because 250 mL as shown on the table contain 3 alcohol units and there are three 250 mL in 750 mL.

Type of Drink Number of Alcohol Units
Single small shot of spirits* (20 ml, ABV 40%) 0.80 units
Single small shot of spirits* (25 ml, ABV 40%) 1.00 unit
Single small shot of spirits* (29.57 ml, ABV 40%) 1.18 units
Single shot of spirits* (35 ml, ABV 40%) 1.40 units
Single small shot of spirits* (40 ml, ABV 40%) 1.60 units
Single small shot of spirits* (50 ml, ABV 40%) 2.00 units
Red/white/rosé wine (175 ml, ABV 12.0%) 2.10 units
Red/white/rosé wine (250 ml, ABV 12.0%) 3.00 units
Red/white/rosé wine (175 ml, ABV 13.0%) 2.28 units
Red/white/rosé wine (250 ml, ABV 13.0%) 3.25 units
Dry gin (175 ml, ABV 43.1%) 7.54 units
Dry gin (250 ml, ABV 43.1%) 10.78 units
Lager/beer/cider (250 ml, ABV 4.0%) 1.00 unit
Lager/beer/cider (275 ml, ABV 4.0%) 1.10 units
Lager/beer/cider (330 ml, ABV 4.0%) 1.32 units
Lager/beer/cider (340 ml, ABV 4.0%) 1.36 units
Lager/beer/cider (375 ml, ABV 4.0%) 1.50 units
Lager/beer/cider (440 ml, ABV 4.0%) 1.76 units
Lager/beer/cider (250 ml, ABV 5.0%) 1.25 units
Lager/beer/cider (275 ml, ABV 5.0%) 1.38 units
Lager/beer/cider (330 ml, ABV 5.0%) 1.65 units
Lager/beer/cider (340 ml, ABV 5.0%) 1.70 units
Lager/beer/cider (375 ml, ABV 5.0%) 1.88 units
Lager/beer/cider (440 ml, ABV 5.0%) 2.20 units
Lager/beer/cider (250 ml, ABV 5.5%) 1.38 units
Lager/beer/cider (275 ml, ABV 5.5%) 1.51 units
Lager/beer/cider (330 ml, ABV 5.5%) 1.82 units
Lager/beer/cider (340 ml, ABV 5.5%) 1.87 units
Lager/beer/cider (375 ml, ABV 5.5%) 2.06 units
Lager/beer/cider (440 ml, ABV 5.5%) 2.42 units
Lager/beer/cider (250 ml, ABV 6.0%) 1.50 units
Lager/beer/cider (275 ml, ABV 6.0%) 1.65 units
Lager/beer/cider (330 ml, ABV 6.0%) 1.98 units
Lager/beer/cider (340 ml, ABV 6.0%) 2.04 units
Lager/beer/cider (375 ml, ABV 6.0%) 2.25 units
Lager/beer/cider (440 ml, ABV 6.0%) 2.64 units

*Gin, rum, vodka, whisky, tequila and sambuca.