The size of your countertop will depend on a number of factors and is specific to each layout (non-straight wall, drainage holes to be taken into account, etc.) - you'll need to check this with your fitter. 📐

As for the overhang towards the front of the countertop, for perfect alignment allow 20mm (thickness of the fronts) + 2-3mm margin (which corresponds to the space between the cabinet and the door).
From a practical point of view, we suggest protruding the countertop by an extra centimetre, as this can make it easier to reach underneath (for cleaning, for example).
You can also extend the countertop so that it is level with the handles. You will then need to add the width of the handles to the previous dimensions.