In an effort to make this easier, I came up with a measure called a Standard Caffeine Dose, or a SCAD. A SCAD is seventy-five milligrams. This is a handy standard, roughly equal to a shot of espresso, five ounces of coffee, one 8.4-ounce Red Bull, two cans of Coke or Pepsi, a sixteen-ounce Mountain Dew, or a twenty-ounce Diet Coke (which has higher caffeine concentrations than Coke).