What are lumens - and how much light does a room need?

Minimalist lamp with light cone as a symbol for lumen and lux

Lumen (lm) indicate how much light a source emits in total. Do not confuse this with watts (energy consumption) or lux (illuminance at the location). In practice, this means that the more lumens the more light - but how bright it feels is ultimately decided by the lux-number in the room.

The most important terms at a glance

Lumen (lm)

Lumen describes the luminous flux - i.e. the total amount of light emitted of a source.

Lux (lx)

Lux is the illuminance at the location. 1 lx = 1 lm/m². Crucial for visual comfort and task lighting.

Watt (W)

Watt indicates the power consumption (energy consumption). Says not directly about the brightness.

Remember: Lumen = how much light the lamp produces. Lux = how much light arrives. Watt = what the lamp consumes.

This is how many lumens you need for your room

Select room type:Room size in m²:

The calculation is based on typical standard values (e.g. DIN EN 12464-1). In practice, the requirement may vary slightly depending on the room, furnishings and lamp quality.

Why the right amount of light counts

Too little light strains the eyes, too much light dazzles and is uncomfortable. The right lux-number ensures visual comfort and a room matching atmosphere. For activities such as reading, cooking or working, you need higher values than for sitting comfortably.

Bright, friendly kitchen with cozy 3000K lighting and evenly illuminated work surface

Orientation values: recommended lumens per m² per room

Area / activity	Recommended brightness (lumen/m²)	Note
Living room (ambient light)	100-150 lm/m²	Cozy; reading corner separately brighter
Reading corner / zone light	300-500 lm/m²	Targeted additional lighting
Dining area	150-250 lm/m²	Pleasant, glare-free
Bedroom (ambient light)	50-150 lm/m²	Calming; dressing room brighter
Children's room	100-150 lm/m²	Similar to living room; additional spots possible
Dressing room / choice of clothes	200-300 lm/m²	Good color recognition
Kitchen (general)	250-300 lm/m²	Basic brightness for the room
Kitchen (work surfaces)	500 lm/m²	Under-cabinet or zone lighting
Bathroom (general)	250-300 lm/m²	Diffuse ambient light
Bathroom (mirror / make-up)	300-500 lm/m²	Lateral / circular, without shadow
Study / home office	250-350 lm/m²	For concentrated work; selectively more possible
Corridor / stairs	100-150 lm/m²	Orientation without glare
Cellar / storage room / hobby room	100-300 lm/m²	Practical functional light
Hobby / precision work	750-1000 lm/m²	Local additional lighting

Note: Technically equivalent to 1 Lux always 1 lumen per square meter. In practice, illuminance is often measured in lux on a surface (e.g. at a desk). For the overview in the table, we therefore use Lumen per m² - which is easier to understand when calculating the total requirement and leads to the same result.

Note: In practice, you sometimes need a little more lumen because not all the light reaches the surface and lamps become weaker over time. The values in the table are based on current recommendations (e.g. DIN EN 12464-1) and have been rounded in line with practical requirements.

What you can also look out for:

Beam angle & distribution: Decides whether the light is broadly diffused or rather pinpoint.
Bright or dark areas in the room: Light-colored walls, ceilings and furniture reflect more light - making the room appear brighter. Dark surfaces "swallow" light, so the room appears darker despite having the same lumens.
Installation height & position: the higher or further away the lamp, the larger the illuminated area, but the weaker the brightness on the floor or work surface.
Avoid glare: Lamps should be bright without dazzling the eye.
Light quality (CRI / R₉): Shows how natural colors appear. A high CRI ensures that skin tones, clothing or food appear unadulterated.
Color temperature: warm white (approx. 2700 K) appears cozy, neutral white (approx. 4000 K) rather clear and activating.

Cozy living room with atmospheric, warm lighting

FAQ - short & crisp

How do I measure lux?

With a luxmeter in the working or occupied area. It is best to take several measurement points and calculate the average value.

Are watts still relevant?

What counts for brightness lumens (source) and lux (at the location). Watt only describes the energy consumption.

Do I have to adhere strictly to the recommendations?

No - the values given are guide values. Every room is different and personal taste also plays a role. The recommendations provide a sensible direction, but it doesn't have to be an exact fit.

Are more lumens always better?

No - although lumens indicate how much light a lamp produces, they say nothing about the quality of the light of the light. The color rendering (CRI/Ra value) and a spectrum that is as natural as possible are also decisive. A lamp with slightly fewer lumens but high light quality can have a much more pleasant and healthier effect on your well-being than a very bright but "artificial" light.

Find out more: CRI and color rendering of LEDs

Conclusion

With the orientation values in Lumen per square meter and the interactive calculator, you can quickly estimate the lighting requirements for your rooms. However, don't just pay attention to brightness, but also to factors such as distribution, reflection, Ageing and the quality of the light (CRI and spectrum). The result is lighting that is not only bright enough, but also feels pleasant and appropriate for the use - from a cozy living room to concentrated work.