How many lumens per m²? The quick guide

Too dark, and you squint. Too bright, and it feels like an office. Here is the simple way to judge the right amount of light for a room, without complicated maths.

Lumens, not watts

For years we chose bulbs ‘by the watt’. With LED, wattage no longer tells you anything about the light produced: what counts is the lumen (lm), the amount of light emitted. More lumens = more brightness.

The rule: area × target lux

Every room has a lighting requirement, expressed in lux (lumens per m²). The formula fits on a single line:

Lumens needed = area (m²) × recommended lux

Room-by-room guidelines

• Living room: 100 to 150 lux (ambient), up to 300 for a reading nook
• Bedroom: 100 to 150 lux, soft light
• Kitchen: 250 to 300 lux (more on the worktop)
• Bathroom: 200 to 300 lux, especially around the mirror
• Study: 300 to 500 lux to work without eye strain
• Hallway / entrance hall: 100 lux is enough

A real-life example

A 20 m² living room with a target of 150 lux: 20 × 150 = 3000 lumens in total. Spread them across a ceiling light, a floor lamp and an accent lamp — never a single source.

The secret: layer your sources

Beautiful light does not come from one large fitting, but from three layers: general light (ceiling light), task light (desk lamp, wall light) and ambient light (table lamp, dimmer). That is what gives a room depth and comfort in the evening.