For a standard 32 oz. sized french press measure out 53 grams coffee, that's about half a cup of coffee. You'll need to boil 800 grams (28 ounces or 3 & 1/2 cups) of water. Protip: If you're using the smaller 12 oz french press, all the steps remain the same, only the measurements are 18g coffee to 270g water.3 tbsp to 9.5 oz by volume. If you have a completely different sized french press, just see what fits naturally using a 1:15 coffee to water brew ratio.Step 2.rotip: If you're using the smaller 12 oz french press, all the steps remain the same, only the measurements are 18g coffee to 270g water. 3 tbsp to 9.5 oz by volume. If you have a completely different sized french press, just see what fits naturally using a 1:15 coffee to water brew ratio. Step 2.