Drunken Driving in Hong Kong means Blood Alcohol Concentration (BAC) level exceeds 0.05%. We suggest the following formula for calculating BAC. However, since there are many factors such as ethics, health, sex that can affect individuals' BAC, this formula can only be used for estimation.(EBAC)

SD(Standard Drink) Beer: each unit around 355ml, Wines: each unit around 148ml, Liquor/Spirits: each unit around 44ml

BW(Body Water Constant) Male 0.58, Female 0.49

WT(Body Weight) kg as measure unit

MR(Metabolic Rate) Male 0.015, Female 0.017

DP(Drink Period) hours as measure unit

Examples:

A 65 kg Male had  4 units of wines in 4 hours, his BAC is

A 50 kg Female had 4 units of wins in 4 hours, her BAC is 

Different levels of BAC might incur different reactions on individuals. The following are general reactions for reference.

0.02 - 0.03 BAC Mildly relaxed, a little lightheaded, slight euphoria.

0.04 - 0.06 BAC Emotions intensified, euphoria, lowering of caution, feeling of well-being.

0.07 - 0.09 BAC Slight impairment of balance, speech, vision, reaction time, hearing, reason and memory.

0.10 - 0.125 BAC Loss of good judgement and significant impairment of motor coordination, slurred speech.

0.13 - 0.15 BAC Blurred vision, major loss of balance, dysphoria (anxiety, restlessness), perception and judgement severely impaired.