There are a number of factors that affect how drunk you will get when drinking alcohol.
Weight is one important factor.
The total concentration of alcohol in your blood measures how drunk you are, so if you are small, your blood alcohol percentage will be higher than someone who drinks the same amount but who is larger. The amount of alcohol that you are accustomed to drinking also makes a difference. People who drink often can drink more because they have built up a tolerance, but if they continue to drink over a long period, it will take less alcohol to become intoxicated than the average person. The amount of food in your stomach also makes a difference because alcohol is absorbed directly from the stomach into the bloodstream. Therefore, eating something before you drink, especially if it is high in protein such as cheese, meat or eggs, will slow alcohol absorption.