Lighting Journal

How Wide Should a Vanity Light Be Over a Bathroom Mirror?

How Wide Should a Vanity Light Be Over a Bathroom Mirror?

Short answer: For a horizontal vanity light above a bathroom mirror, measure the mirror first and keep the light's full width within it. That is the starting advice in Kichler's bathroom-lighting guide. Then decide how much clear space you want at the ends and whether the light actually illuminates the face for the way you use the mirror.

Measure the mirror, not the vanity cabinet

Write down the mirror's visible width, its top edge and the distance to any side wall or cabinet. Compare that width with the complete end-to-end length of the fixture, including its caps. A cabinet may be wider than the mirror; sizing from the cabinet alone can produce a bar that extends beyond the glass. Center the proposed light over the mirror and sink before the electrician fixes the wall box.

Try a 30-inch mirror as an example. A 22.8-inch bar leaves (30 − 22.8) ÷ 2 = 3.6 inches of mirror at each end when centered. A 29.5-inch bar leaves only 0.25 inch at each end. Both stay within the mirror, but the first looks more contained and the second nearly spans it. The arithmetic is a way to compare proportions, not a rule about how much light either bar produces.

Compare the actual fixture choices

The Auvielight Mirror Linear Vanity Light currently lists five lengths: 13.8, 17.7, 22.8, 29.5 and 39.4 inches. Its product description specifies a brass body, acrylic diffuser, integrated warm LED and hardwired installation; the selector offers antiqued brass and black finishes. For the 30-inch example, the 22.8- and 29.5-inch versions make the comparison above possible. The 39.4-inch option would be wider than that mirror.

Check the face light and the bathroom location

A bar over the mirror can leave shadows under the brow or chin. Kichler suggests side sconces where wall space permits and a separate general-light layer for the room. The NKBA's 2026 bath-trends release likewise reports a strong emphasis on task lighting in primary bathrooms. These are planning ideas; they do not establish the output of a specific fixture. If you use only an overhead bar, check its measured output and the face view from your normal standing position.

The Auvielight listing identifies this product for bathrooms but does not state a damp-location or wet-location rating. Confirm the proposed position and its electrical suitability with the seller and a qualified installer before purchase. Its warm-light label also gives no exact Kelvin number; our Kelvin guide explains why a color name alone is imprecise.

Browse Wall Lights for other mirror and side-light shapes, then All Lighting for the room's separate ceiling layer. Choose the bar from measured mirror width and the face view, with installation details checked for the actual bathroom.

Sources

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