The bathroom is the room where people most often get the amount of light wrong: too little and shaving becomes guesswork, too much and the evening bath feels like an exam hall. The right answer is not a single figure, because a bathroom has two different needs: general lighting to move around, and mirror lighting to get ready.
This guide is part of our series How many lumens per room, with the detail for the living room, bedroom, kitchen and home office.
Here is the calculation method, the chart by floor area from 3 to 10 m², how to split light between ceiling, mirror and ambience, and the safety rules that apply near water.
The basic rule: lux × floor area
We work with two units. Lux measures the light that lands on a surface, which is what lighting recommendations use. Lumens measure the light a fixture produces, which is what is printed on the box. The link between the two is simple:
Lumens needed = floor area (m²) × recommended lux
For a bathroom, the recommended general level is between 200 and 300 lux. Use 200 lux if the room is mostly for baths and showers, 300 lux if you do your make-up, shave or style your hair there every morning. A 6 m² bathroom at 300 lux therefore needs 6 × 300 = 1,800 lumens of general lighting.
That total does not include the mirror, which has its own rule. This is the most common mistake: a correctly sized ceiling light, and a face in shadow at the basin.
Two needs, two amounts of light
General lighting: 200 to 300 lux
This is the light that lets you see the whole room without dark corners: walking in, grabbing a towel, cleaning. It usually comes from the ceiling. A 1,500 to 2,000 lumen LED ceiling light covers a 5 to 7 m² bathroom. Beyond that, move to several light points rather than one overpowered ceiling light, to avoid harsh shadows.
The mirror: 400 lux minimum on the face
Most of the useful time in a bathroom is spent at the mirror: shaving, make-up, hair. You need around 400 lux on the face, which means 400 to 600 extra lumens split between two wall lights, one on each side of the mirror, at eye level, i.e. 160 to 170 cm from the floor. Side light illuminates the face evenly; a single spot above the mirror digs shadows under the eyes and nose.
Evening ambience: the dimmer
For a relaxing bath, you go well below the getting-ready level. A dimmer on the general lighting, or a separate ambient source, lets you move from a functional room in the morning to a soft one in the evening without changing fixtures.
Chart: lumens by bathroom floor area
The chart applies the lux × m² rule to general lighting, then adds the mirror share, which is the same whatever the floor area.
| Floor area | General at 200 lux | General at 300 lux | Mirror on top | Recommended total |
|---|---|---|---|---|
| 3 m² (cloakroom with basin, shower room) | 600 lm | 900 lm | 400 to 600 lm | 1,000 to 1,500 lm |
| 5 m² | 1,000 lm | 1,500 lm | 400 to 600 lm | 1,400 to 2,100 lm |
| 7 m² | 1,400 lm | 2,100 lm | 400 to 600 lm | 1,800 to 2,700 lm |
| 10 m² | 2,000 lm | 3,000 lm | 400 to 600 lm | 2,400 to 3,600 lm |
A 5 to 7 m² bathroom is almost always solved with a 1,500 to 2,000 lumen ceiling light and two mirror wall lights of 200 to 300 lumens each.
Walls matter: white or light tiles bounce back a large share of the light, dark or matt tiles absorb a lot of it. In a dark bathroom, aim for the top of the range.
How to spread those lumens around the room
On the ceiling: the main source
A wide-diffusion ceiling light rather than a single spot. If you prefer recessed spots, count one spot per 1 to 1.5 m² to keep the lighting even, and an IP65 rating for those placed above the shower.
Around the mirror: the wall lights
Two side wall lights at eye level. If the layout only allows lighting above the mirror, choose a strip light as wide as the mirror, never a concentrated spot, to limit shadows.
As a complement: ambient light
An LED strip under the vanity unit or behind the mirror, or a rechargeable lamp placed on a shelf away from water splash zones. This layer is not for seeing, it is for breathing.
The safety zones, in one minute
The French standard NF C 15-100 divides the bathroom into zones around the bath and shower. In short: in the water, nothing or almost nothing; directly above the shower or bath, IP65 and 12 V extra-low voltage; within 60 cm around it, IP44 minimum; in the rest of the room, no strict obligation but IP44 remains recommended. The zone-by-zone detail is in our bathroom lighting guide, and the ratings are decoded in the IP rating guide.
Colour temperature and colour rendering
The number of lumens is not everything. At the mirror, colour temperature changes the result in a very practical way: a neutral white of 4,000 K reproduces daylight and shows the true colours of skin and make-up. A warm white of 2,700 K is perfect for the evening bath, but make-up applied under that light will look too dark once you step outside.
Also aim for a colour rendering index (CRI) of 90 or above. Under a low CRI, skin looks greyish and shades blur together. Good-quality LEDs reach that level at no notable extra cost. To go further, read which colour temperature to choose.
The 5 mistakes that ruin a well-sized bathroom
- A single spot above the mirror: the lumen total is right, but the face is in shadow.
- Betting everything on the ceiling light: 3,000 lumens on the ceiling do not light a shave better than 1,500 well-placed lumens plus two wall lights.
- Forgetting the dimmer: the morning getting-ready light is too strong for the evening bath.
- Warm white at the mirror: pleasant, but misleading for make-up.
- Ignoring the IP rating: a dry-indoor fixture 40 cm from the shower is an electrical risk and an uninsured claim.
Frequently asked questions about bathroom lumens
How many lumens for a small 3 m² bathroom?
Between 600 and 900 lumens for general lighting, plus 400 to 600 lumens for the mirror, so 1,000 to 1,500 lumens in total. In such a small space, two mirror wall lights can almost provide the general lighting on their own.
Is a 1,000 lumen ceiling light enough?
For a 3 to 5 m² bathroom at 200 lux, yes for general lighting. It does not replace mirror lighting, which must come from the sides.
How many lumens for mirror lighting?
Count 400 to 600 lumens in total, split between two wall lights on either side of the mirror, at eye level, in neutral white 4,000 K and with a CRI of 90 or above.
Do you need more lumens in a windowless bathroom?
The lux × m² calculation stays the same, but without daylight the room depends entirely on artificial light all day long. Aim for the top of the range, 300 lux, and a dimmer to soften the evening.
Can you use a rechargeable lamp in a bathroom?
Only away from the water zones, placed on a shelf or ledge more than 60 cm from the shower and bath, and only if the fixture does not need an IP rating for that spot. It serves as ambience, never as the main lighting.
The right bathroom light, in short
Two layers, two amounts: 1,500 to 2,000 lumens on the ceiling for a 5 to 7 m² room, 400 to 600 lumens on either side of the mirror, neutral white 4,000 K in the morning, a dimmer for the evening, and IP ratings respected near water. To size the other rooms of the house, see the whole series how many lumens per room.
Lumora's advice
Size the mirror first, the ceiling second. The mirror is where light has a precise use every morning; the ceiling light only completes it.
