My math's fine. I think you misunderstood my post. I was just considering metric and imperial sizes thus included both sets of units.

The first reply to your post shows the math.

Even the 'increased' 240mg in the energy drink is just equivalent to 'regular' coffee due to it being 16oz/473mL can.

As I said though. Much easier to gulp down half a litre of sugary soda than half a litre of oily thick espresso.