Example is 400mm high and 1000mm 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.
Base is recessed 20mm.
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!