Example is 600mm high and 900mm wide. Hand painted in Bone by Farrow & Ball
This is suitable for a canopy extractor that fits into the underneath of the cabinet like this SMEG model:
Make sure that this cupboard is 100mm wider (50mm each side) than hob.
Also make sure that you check your hob manual (or web-site) to get the minimum height from hob to extractor. As a guide it is likely to be about 650mm for an electric hob or 760mm for a gas hob, but you MUST install according to your hob manufacturers instructions!
Make sure your cupboard has enough height for extractor and ducting as in the pic above.
Up to 800mm = 1 panel, 801mm - 1400mm = 2 panels