When it comes to range hoods, size definitely matters. The general rule of thumb is that your range hood should be at least as wide as your cooktop or range. So, for a 30” range, you’ll need a 30” range hood.
Of course, there are other factors to consider when choosing a range hood besides just width. For example, you’ll also want to think about the height of the hood and the CFM (cubic feet per minute) rating.
The height of the hood is important because you want to make sure it will capture all of the smoke and fumes generated by cooking. A good rule of thumb is that the bottom of the range hood should be about 24-30” above the cooktop.
As for CFM, this refers to the amount of air movement created by the range hood. The higher the CFM, the better it will be at removing smoke and odors from your kitchen. For a 30” range hood, you’ll want a minimum CFM rating of 400.