I think, in the spirit of accuracy, that they should more rigorously define the capacity of the cup they are measuring.

For example, my coffee mug clocks in at 750ml. If I were to have two of those every morning, I would be vibrating through solid walls and floors like The Flash.

On the flip side, my mother’s coffee cup barely cracks 200ml. On hard days I’d be propping my eyelids open with toothpicks by mid-afternoon with just two of those cups.