You want something that will cover the width of the mirror as closely as possible - a 3-4 light fixture. I would have chosen a narrower cabinet in order to have single sconces on each side of the mirror. Sconces at eye level provide much better lighting of your face than fixtures over mirrors.

@kandrewspa if i did i 30 medicine cabinet would 2 sconces work. my vanity on one side is against a wall.

A 30" medicine cabinet only leaves you with 9", or 4.5" on each side. It would be difficult to find a sconce that narrow and you need to allow space on either side of it. A 24" medicine cabinet would be better. This isn't the best angle of the vanity in this picture, but I think this vanity is close to the size you are going to have.

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