What factors influence blood alcohol concentration (BAC)?

A lot of factors can influence your BAC. These include:

• The amount and type of alcohol consumed
• The rate of drinking and time since the last drink
• The amount of alcohol remaining in the stomach
• Other foods or liquids in the stomach
• The amount of alcohol already metabolised by the liver
• Your general health
• The condition of your liver
• Your metabolic rate
• Physical factors (such as body size and lean tissue to body fat ratio)
• Volume of water in body tissues – can be affected by things such as medication, illness and your menstrual cycle

As everyone’s BAC can be different, the only way to be sure is to not drink alcohol if you are going to drive.