It depends on which coffee you are drinking. Regular brewed coffee has 60-120mg in an 8 oz cup. If you prefer instant coffee then an 8 oz cup has 70mg. Even decaf coffee has a small amount of caffine 1 – 5mg for an 8 oz cup. Popular in my office in the afternoon is a double expresso. In that small 2 oz cup there are 45 – 100mg of caffine. You may wonder why there is a range on some of these type of coffee. It’s due to the numerous varieties available and each has a different caffine content. The way a coffee is roasted can also affect the caffine content.