Bathrooms get renovated more often than almost any other room, and the lighting is usually the last thing decided and the first thing regretted. Tiles get weeks of deliberation. The light above the mirror gets picked in ten minutes from whatever the showroom had in stock.
This guide is about the fixture decision specifically: what to put where, how wide it should be, and which of the numbers on the box actually matter once it is on the wall.
Three configurations, and how to choose between them
Almost every bathroom ends up with one of three arrangements at the mirror. They are not equally good, but they are not equally possible either, and the right answer usually depends on your wall rather than your preference.
Configuration one: a single bar above the mirror. The most common, the easiest to install, and the weakest optically. Light falling from above a face deepens the shadows under the brow, nose and chin rather than filling them. You can mitigate this substantially by going wide, which we will come back to, but you cannot eliminate it.
Choose this when there is no usable wall either side of the mirror, when the mirror is set into a cabinet, or when you are replacing like for like without moving wiring.
Configuration two: a pair of sconces flanking the mirror. Optically the best option, because the light arrives at the face horizontally and fills shadows instead of casting them. It also frees the wall above the mirror entirely, which matters if you have a tall mirror or a sloped ceiling.
Choose this when you have at least 4 inches of clear wall on each side of the mirror and you are running new wiring anyway.
Configuration three: both. A bar above for general fill, sconces at the sides for the face, on separate switches. This is what a well-specified bathroom looks like and it is not as extravagant as it sounds, since the sconces can be modest.
If you can only afford one circuit and you have the wall space, put it in the sconces. The overhead is easier to add later than the side wiring is.
Sizing, which is where most of the errors happen
For a bar above the mirror, the fixture should be somewhere between 60 and 75 percent of the mirror width, and it should never be wider than the vanity below it. A 30 inch mirror takes an 18 to 22 inch bar. A 48 inch mirror takes 28 to 36 inches.
People routinely buy too narrow, usually by a lot. A 12 inch fixture over a 36 inch mirror concentrates all the output into a small overhead point, which is the exact condition that produces harsh shadows. Width is what softens overhead light. If you are committed to configuration one, buying the widest fixture that fits is the single most effective thing you can do.
For side sconces, height matters more than width. Mount the centre of each fixture at 60 to 66 inches from the finished floor, and set them 36 to 40 inches apart where the mirror allows. If the mirror is narrow and they end up closer than 30 inches apart, they will start behaving like an overhead fixture split in two, which defeats the purpose.
Pick sconces that emit sideways or in both directions rather than downward only. A downward-only sconce at eye level puts a hard edge across the face and a bright spot on the counter.
Linear bars that come in several widths let you match the mirror properly instead of settling for whatever length was in stock.
Wet zones and IP ratings
Bathrooms are divided into zones based on how much water a fixture is likely to meet, and each zone has a minimum ingress protection rating. The exact zone definitions vary between countries, but the underlying logic is consistent everywhere.
- Inside the bath or shower enclosure — the wettest position. Requires a sealed fixture, typically IP65, and often low voltage depending on local rules.
- Directly above or immediately beside a bath or shower — IP44 as an absolute minimum, IP65 preferred.
- Around the basin and mirror — IP44 is the sensible specification. Steam and splash both reach here.
- The rest of the room — an ordinary indoor-rated fixture is usually acceptable, though a dedicated bathroom fixture will survive the humidity better over time.
The rating is only as good as the installation. A properly sealed IP44 fixture mounted over an unsealed cable entry is not IP44 in practice. Ask your electrician to seal the back box, not just fit the fixture.
Where a fixture sits near a bath, a purpose-built waterproof design is worth the premium. Something like the American waterproof bathroom fixture with white glass shade is built for the position rather than adapted to it.
The specification that decides how you look
Two numbers matter at a mirror, and neither is wattage.
Colour rendering (CRI). This measures how faithfully a light source reproduces colour. Budget LEDs frequently sit around CRI 70 to 80, which under-renders reds and makes skin tones read grey. At CRI 90 and above, complexions look like themselves. For anywhere you shave, apply makeup, or assess your own face, this is the specification to insist on. Elsewhere in the house you can be relaxed about it. Here you cannot.
Total output. Aim for roughly 1600 to 2000 lumens reaching the mirror area. Split across two sconces that is 800 to 1000 each. A single bar doing the whole job needs to be at the upper end.
On colour temperature, 3000K to 4000K is the working range for a bathroom, and there is a longer discussion of what those numbers mean in our guide to understanding colour temperatures. The short version for this room: 3500K if you are undecided, warmer if the bathroom doubles as somewhere you relax, cooler if it is a morning-only room.
Exposed-bulb designs need frosted lamps at mirror height. A bare filament in the eyeline is uncomfortable regardless of how good the fixture looks unlit.
Finishes that survive the room
Bathrooms are the harshest finish environment in a house. Constant humidity, temperature swings, and aerosol products all attack plating and lacquer.
Chrome and brushed nickel are the durable choices and will look the same in ten years. Matte black holds up well but shows limescale spots in hard water areas, so expect to wipe it. Brass and copper will patina, sometimes unevenly, and whether that is a feature or a fault depends entirely on your taste — but decide before you buy, not after.
Glass shades collect water spots. Frosted and opal glass hides them far better than clear glass does, and also solves the exposed-bulb problem at the same time.
Practical details worth settling before installation
Decide fixture positions before tiling. Once the wall is tiled, moving a fixture means cutting tile. Mark the centres and agree them with whoever is tiling.
Check mirror cabinet door swing. If your mirror is a hinged cabinet, side sconces need clearance for the door arc. Measure it open, not closed.
Confirm the switch position. Many jurisdictions require bathroom switches to be outside the room or of a pull-cord type. Your electrician will know the local rule; it is worth asking early because it affects where the circuit runs.
Integrated LED or replaceable bulb. In a bathroom we lean toward integrated units, because a sealed body resists moisture better than a lamp holder does. The trade-off is that you replace the fixture rather than the bulb when it eventually fails.
Dimming. Worth doing if the bathroom is used at night. Confirm the fixture is dimmable before ordering, since many integrated LED units are not.
A working specification
- Side sconces at 60–66 inches from the floor, 36–40 inches apart, wherever the wall allows.
- If going overhead instead, size the bar at 60–75 percent of mirror width.
- IP44 minimum around the basin, IP65 in or above a shower.
- CRI 90 or better. Non-negotiable at a mirror.
- 1600–2000 lumens total at the vanity, 3000K–4000K.
You will find vanity bars and bathroom-suitable sconces throughout our wall lights collection, with the contemporary designs grouped under modern wall lights. If you want a room-by-room overview rather than a deep dive on one space, our complete home lighting guide covers the whole house.