Your drinking Apps and tools Unit information A unit is a measure of the amount of alcohol in a drink. One unit is 10ml or 8g of pure alcohol. How much alcohol (how many units) there is in your drink can vary enormously depending on the size, strength and type of drink. One drink does not simply equal one unit, this is why it is important to be aware of the units you consume. Understanding how many units you’re consuming or realising that alcohol can cause unhealthy weight gain may make you want to change your drinking habits. You can make informed choices and start to make positive changes to your lifestyle, limiting the impact that alcohol has on you. Use our unit calculator to find out how many units are in your drink.