First choose a style: A, B, C or Espresso. Then think about how much coffee you drink, or, if it is a gift, how much your friend drinks. An easy calculator is one cup a day equals 15 to 20g. How often would you like it? choose frequency and once you have done all that, it is up to us to make sure that you never run out again. To make sure there are no arguments on a Saturday morning, no empty-cupboard-silent-screams.