How many spots do you need in the bathroom?

Recessed spotlights bring calm and atmosphere to a bathroom, but too few spots leave the room dim and too many give a hard, busy ceiling. How many spots you need depends on the size of the bathroom, the colour of the walls and what you do in the room. In this blog we give you a calculation guide to plan the number of spots. The electrical side, so fitting and connecting, is always for a certified electrician.

👷 This is a planning blog, not an installation guide. Bathrooms have strict electrical rules: there are zones, each with its own minimum IP rating, and the transformer or driver must be in the right place. Fitting and connecting recessed spotlights is work for a certified electrician. Calling in a professional is never unnecessary: they know the rules, assess your ceiling and make sure everything works safely.

How much light does a bathroom need?

Light is measured in lumens (lm), not watts. Watts only tell you how much power a lamp uses. As a rule of thumb for general lighting in a bathroom, count on roughly 300 to 400 lumens per m². With light tiles you are at the lower end of that range. With dark walls or matt natural stone you need more light, because dark surfaces absorb a lot of it.

• General lighting (ceiling spots): around 300 to 400 lm per m².
• Extra light at the mirror: preferably mirror lighting, for example an LED bathroom mirror.
• These are guideline values. Your electrician or lighting adviser looks at your room and may deviate from them.

How to calculate the number of spots

The calculation guide has three steps:

1. Measure the bathroom with a tape measure with auto-lock and work out the area: length x width in metres.
2. Multiply the area by 350 lumens (the middle of 300 to 400). That is the total number of lumens you need.
3. Divide that number by the lumens of one spot. A typical LED recessed spot gives about 350 to 500 lumens. Round up.

💡 Draw a floor plan on paper with a carpenter pencil and sketch the spots on it. You immediately see whether the layout works before you show the plan to your electrician.

Examples for 3, 4 and 6 m²

The numbers below are worked examples with spots of about 400 lumens. An electrician adjusts them to your ceiling, your walls and the position of the mirror.

• 3 m² (for example a small shower room): 3 x 350 = about 1,050 lumens. That is 3 spots of 400 lumens (1,200 lumens).
• 4 m²: 4 x 350 = about 1,400 lumens. That is 4 spots of 400 lumens (1,600 lumens).
• 6 m²: 6 x 350 = about 2,100 lumens. That is 6 spots of 400 lumens (2,400 lumens), arranged in two rows of three.

Want a little more headroom? Choose a dimmable spot. Then you can set the light brighter during the day and softer in the evening.

Where do the spots go?

A good layout matters as much as the number. A few guidelines for your plan:

• Spread the spots evenly over the ceiling, preferably in a regular pattern, so there are no dark patches.
• Distance to the wall: keep roughly 40 to 60 centimetres clear from the wall. Spots too close to the wall give streaks of light on the tiles. Spots too far away leave the wall dark.
• Distance between spots: about 80 to 120 centimetres, depending on ceiling height and the beam spread of the spot.
• At the mirror: do not place spots directly above the mirror but slightly in front of the person standing there. The light then falls on the face instead of casting shadows underneath.
• At the shower: this is where the IP rating comes in. Where water splashes, a higher protection rating is needed. Exactly what is allowed and where is decided by the electrician, based on the zones in your bathroom.
• Beam spread: a wide beam angle (around 60 degrees or more) gives soft, even light. A narrow angle (around 36 degrees) suits accent lighting, for example on a niche or a beautiful wall.

⚠️ Whether a spot is allowed in a particular place in a bathroom depends on the zone and the IP rating. Always plan your ceiling together with a certified electrician and let them decide the final positions.

Which colour and quality of light should you choose?

• Warm white, 2700 to 3000 kelvin: gives a cosy, calm atmosphere. It suits general lighting in a bathroom where you want to relax.
• Neutral white, around 4000 kelvin: gives clear, natural light. That is pleasant at the mirror, for example when shaving or applying make-up. If you use mirror lighting, 4000 kelvin fits well there.
• CRI 90 or higher: the colour rendering index shows how natural colours look. With CRI 90+ skin, tiles and make-up look the way they really are.
• Dimmable: a dimmer lets you set the light to the time of day. Make sure the spots and the driver are suitable for dimming. Your electrician advises which combination works.

💡 Do not mix too many colour temperatures in one room, except deliberately at the mirror. Choose one warm-white base and a neutral white accent at the basin.

Spots and mirror lighting: a good pair

Ceiling spots provide the basic lighting, but at the basin they easily cast shadows under the chin and eyes. That is why extra mirror lighting is a good choice. An LED mirror with lighting or wide LED mirror has lighting in the mirror itself, and a mirror cabinet or mirror cabinet in white adds storage, with the light above the basin planned separately. How to hang the mirror itself is covered in our blog on hanging a bathroom mirror. The electrical connection of a lit mirror is also left to the electrician.

What to look for with IP rating, zones and transformer

We explain this only so you can have a good conversation with your electrician. They make the choices.

• IP rating: the IP code shows how well a fitting is protected against moisture and dust. IP44 is protected against splashing water. IP65 is also protected against water jets, so it suits places that get really wet, such as above or near a shower.
• Zones: a bathroom is divided into zones around the bath and shower. Each zone has requirements for the IP rating and for what may be installed.
• Transformer or driver: many LED spots run on low voltage and need a transformer or driver. It must be in a suitable place and accessible for maintenance.
• Installation depth: check with your electrician whether there is enough space above the ceiling for the recessed spots and the wiring.
• Fire safety and insulation: recessed spots in an insulated ceiling need the right type. The professional assesses that too.

Combining with your bathroom design

Light is part of the whole design: tiles, vanity unit, mirror and shower. In our blog on the Saniso bathroom configurator you can read how to lay out your bathroom, and in our blog on tiling a wall you can see how tiles are fitted on the wall to reflect the light later. Glossy tiles and a glass Larga shower enclosure with tray reflect light, matt dark walls absorb it. Take that into account when deciding the number of spots.

Working safely

This is a planning blog and you do not carry out any installation steps yourself. If you do get your hands dirty in the preparation, for example when clearing the bathroom before the electrician arrives, wear work gloves with nitrile coating and safety goggles. Never work on the electrical installation yourself.

Frequently asked questions

How many spots do I need in a 4 m² bathroom?

As a guideline you use about 350 lumens per m². That is around 1,400 lumens. With spots of 400 lumens that comes to 4 spots. Your electrician adjusts this to your ceiling and walls.

Which colour temperature should I choose?

Warm white (2700 to 3000 kelvin) for a cosy atmosphere. At the mirror, neutral white of around 4000 kelvin is pleasant for a clear view.

What does CRI 90+ mean?

The colour rendering index shows how natural colours look under the light. A value of 90 or higher gives accurate colour rendering.

Do the spots need to be dimmable?

They do not have to be, but it is pleasant. Dimmable spots let you adjust the light to the time of day. Ask your electrician for a combination of spot, driver and dimmer that works well together.

May I fit recessed spots in the bathroom myself?

No. Electrics in a bathroom are work for a certified electrician, because of the zones, the IP rating and the transformer. Calling in a professional is never unnecessary.

Where can you find everything for this job?

At Saniso, the online store for DIYers and professionals, you will find tools, materials and personal protective equipment for your job.

• Browse our construction tools and our workwear and safety.
• Create a customer account and order easily.
• Working on a bigger project or want to hand over the job? Request a project quote.
• Book a showroom visit, at least 24 hours in advance.
• Not sure which material suits your job? Get in touch with us.

In doubt about the approach? Feel free to call in a professional.

Saniso – Build your home with Saniso.