Most vanity lighting mistakes aren't about style — they're about size and placement. A light bar noticeably narrower than the mirror reads as an afterthought, and a fixture mounted too high throws shadows under your brow and chin exactly where you shave or do makeup. The encouraging part is that vanity lighting follows a few proportion rules that have held steady for decades, and they work just as well in a powder room as in a full ensuite. This vanity light size guide walks through those numbers, then covers the two light-quality specs — CRI and colour temperature — that matter as much as the dimensions.
The 75 percent rule for bar lights
When a horizontal fixture mounts above the mirror, size it to roughly 75 percent of the mirror's width. That proportion keeps the fixture visually anchored to the mirror without competing with it. Two boundaries to respect: the fixture should never be wider than the mirror, and never wider than the vanity cabinet below — that's the point where a wall starts to look off, even to people who couldn't tell you why.
| Mirror width | Bar light target (about 75%) |
|---|---|
| 24 in. | 18 in. |
| 30 in. | 22–24 in. |
| 36 in. | 26–28 in. |
| 48 in. | 36 in. |
| 60 in. and up (double vanity) | Two fixtures, one centred over each sink |
On a double vanity with one wide mirror, two smaller bars centred over each sink usually beat a single stretched fixture — the light lands where people actually stand, and the wall reads as two proper stations. If you're still choosing the mirror itself, settle that first: browse bathroom mirrors before the fixture, because the mirror sets the proportions for the entire wall.
Sconces at eye level beat overhead-only
An over-mirror bar is the tidier, simpler install, but it isn't the best way to light a face. Light from above skims down the forehead and leaves the eye sockets and the underside of the chin in shadow. The fix used in makeup rooms and good hotel bathrooms is cross-illumination: a pair of wall sconces flanking the mirror at eye level, so light reaches the face from both sides and the shadows cancel out.
The numbers: mount sconces so their centres sit at about 65 inches above the finished floor — roughly eye level for most adults — and space them 36 to 40 inches apart, or just outside the mirror's edges if the mirror is narrower than that. If your household runs tall or short, shift an inch or two; eye level is the principle, 65 inches is simply the average.
The honest trade-off is wall space. If the mirror runs nearly wall to wall, or a shower enclosure crowds one side, there may be nowhere to land a sconce pair — and that's when a properly sized over-mirror bar earns its keep. The best setups use both: sconces for the face, a modest bar or ambient fixture to fill the room.
Over-mirror mounting height
When the fixture goes above the mirror, aim for 75 to 80 inches from the finished floor to the centre of the fixture — high enough to clear the mirror, low enough that light still reaches faces rather than just the tops of heads. In practice the mirror often dictates the exact spot: leave a small, consistent gap of a few inches between the mirror's top edge and the fixture so the two read as a composed pair.
Check the downlight-versus-uplight question before you buy, too. Many bars mount either way: diffuser facing down puts more light on faces and the counter, while uplight bounces off the ceiling for softer ambient fill. With standard eight-foot ceilings, downlight is usually the right call. And remember that a ceiling fixture on its own is ambient light, not task light — it brightens the room but does almost nothing for your face.
Small bathrooms: making one fixture work
Powder rooms and compact baths often have wiring for exactly one fixture. A few ways to get the most from it, in rough order of preference:
- One honestly sized bar with a diffuser. A frosted or opal shade spreads light far better than exposed bulbs. Keep the 75 percent proportion — an oversized fixture makes a small vanity wall feel smaller, not grander.
- A backlit or front-lit LED mirror. It merges mirror and fixture into one footprint and washes light evenly across the face. Check the published CRI and colour temperature the same way you would for any fixture.
- Slim pendants where sconces can't go. If the wall beside the mirror has no room for a junction box, a compact pendant dropped from the ceiling on each side does the same cross-illumination job. Vanity-scale options in the pendants collection handle this neatly.
Whatever you choose, confirm it's rated for damp locations — standard for bathroom lines, worth double-checking on anything borrowed from a hallway or bedroom range. Sizing decisions cascade in a small room: the vanity sets the mirror width and the mirror sets the light width, so start with a right-sized unit from the vanities collection and work upward. The same measure-first logic applies to the wet side of the floor plan — our shower base size guide covers those decisions.
CRI and colour temperature, in plain terms
Size gets the proportions right; these two spec-sheet numbers decide whether the light itself is any good.
CRI (colour rendering index) measures how faithfully a light source shows colour, on a scale to 100. Plenty of LED fixtures sit around 80, which is fine for a hallway but subtly distorts skin tones at the mirror. For vanity lighting, look for CRI 90 or higher — it's the difference between makeup that looks right in the bathroom and still looks right in daylight.
Colour temperature is measured in kelvin. For bathrooms, 2700K reads warm and cozy, 3000K is the popular middle ground, and 3500K is crisp without tipping into clinical. Avoid 5000K-plus “daylight” at the vanity — it's unforgiving on skin. Many current LED fixtures are CCT-selectable, with a small switch to set the temperature at install time, which is genuinely useful if you're unsure. Whatever you pick, keep every fixture in the room at the same temperature, and put the vanity lights on a dimmer if they support it.
Using Kuzco's vanity range as a reference
If you want a concrete picture of how these rules translate to real products, Kuzco Lighting — a Canadian brand we carry — is a useful benchmark. Its vanity families typically come in several lengths of the same design, which is exactly what the 75 percent rule requires: pick the design first, then the length that fits your mirror, rather than settling for whatever size a style happens to come in. Most of the range uses integrated LEDs, so colour temperature and CRI are baked into the fixture — check the published specs before ordering, because there's no swapping a bulb later. Many of the same families extend into coordinating sconces and pendants, which keeps a bar-plus-flanking-sconce layout, or matching fixtures across two bathrooms, visually consistent.
Frequently asked questions
Can the vanity light be wider than the mirror?
Best avoided. A fixture wider than the mirror makes the mirror look undersized and the wall top-heavy. A slim modern LED bar can stretch closer to full mirror width and still look deliberate, but never go wider than the mirror or the vanity below. If you've fallen for a long bar, the better fix is a wider mirror.
How high should sconces be mounted beside a bathroom mirror?
Centre them at about 65 inches off the finished floor — near eye level — and space a pair 36 to 40 inches apart for a typical single-sink mirror. If household heights vary a lot, bias toward the taller users; light from slightly above eye level is more forgiving than light from below.
What colour temperature is best for vanity lighting?
2700K to 3000K suits most homes, ideally with a CRI of 90 or better — flattering to skin while staying accurate enough for shaving and makeup. Cooler temperatures around 4000K and up show fine detail but tend to feel clinical in a residential bathroom.
Is one light enough for a double vanity?
Usually not. A single centred fixture lights both sinks from an angle, so each person works in partial shadow. Two fixtures, one centred over each sink — or sconces flanking each mirror — give both stations even light and look more deliberate.