To estimate how many lumens a room needs, multiply its floor area by an approximate number of lumens per square metre. There is no universal figure: it depends on the activity, colours, ceiling height and whether you want general lighting or mainly ambience.
As a starting point, a bedroom can work with around 100–150 lumens per square metre, while a kitchen or work area usually needs more. These figures are indicative and should be distributed across several light sources.
Indicative lumens per square metre
| Room or use | Approximate guidance |
|---|---|
| Hallway and entrance | 100–150 lm/m² |
| Bedroom | 100–150 lm/m² |
| Living room, general lighting | 100–200 lm/m² |
| Dining room | 150–250 lm/m² |
| Kitchen, general lighting | 200–300 lm/m² |
| Reading or focused work | 300–500 lux on the surface |
This table does not replace a professional lighting design. It is a guide to help avoid a room being clearly underlit or excessively bright.
A simple formula for estimating lumens
Approximate lumens = square metres × lumens per square metre.
For example, for a 12 m² bedroom using a reference of 125 lm/m²:
12 × 125 = approximately 1,500 lumens.
This does not mean you need a single 1,500-lumen bulb. You can distribute the light between a ceiling lamp, two bedside lamps and an ambient source.
How many lumens does a bedroom need?
A common guide is 100–150 lm/m² for general lighting. In a 10 m² bedroom, that would be approximately 1,000–1,500 lumens in total.
Bedside lamps do not need to provide all of that output. Their role may be ambient or for reading. For more detail, see our guide to choosing a bedside table lamp.
How many lumens does a living room need?
A living room often starts around 100–200 lm/m², but distribution matters more than one total figure. A 20 m² living room might use roughly 2,000–4,000 lumens across several lighting layers.
Ceiling lighting provides a base, while table and floor lamps add depth and let you use lower intensity when relaxing or watching television.
How many lumens does a dining room need?
An indicative 150–250 lm/m² can be useful. However, the main light should focus on the table rather than illuminating the entire room equally.
The height and diameter of the lamp and the opacity of the shade affect how much light reaches the surface. A more closed shade may provide more light on the table and less on the walls.
How many lumens does a kitchen need?
For general lighting, 200–300 lm/m² is a reasonable starting point. Worktops need additional focused lighting because a person standing between the ceiling light and the work surface can cast their own shadow.
In this case, as well as total lumens, it is useful to estimate the lux reaching the worktop.
How many lumens do I need for reading?
For reading, it is more useful to consider light on the page than total lumens in the room. A common guideline is around 300–500 lux on the reading surface, adjusted for age, contrast and personal preference.
Positioning a lamp closer and aiming it correctly can be more effective than installing an extremely powerful bulb. A shade that controls glare also improves comfort.
Factors that may require more light
- Dark walls, floors and furniture.
- High ceilings.
- Very opaque shades.
- Rooms with few reflective surfaces.
- Precision tasks.
- People who prefer or need more illumination.
Factors that can reduce the amount needed
- Light-coloured walls and ceilings.
- Good daylight during the day.
- Lamps positioned close to the task.
- Shades that distribute light efficiently.
- Several sources that avoid dark zones and extreme contrast.
Why you should not put all the lumens into one bulb
One very intense source can create hard shadows, glare and a visually flat room. Distributing the light lets you adapt the space to different moments:
- General lighting for cleaning or receiving guests.
- Task lighting for reading, working or eating.
- Ambient light for relaxing.
In our guide to how many light points a living room needs, we explain how to distribute them.
Frequently asked questions
How many lumens do I need for 10 m²?
It depends on the room. A bedroom might need around 1,000–1,500 lumens of general light, while a kitchen of the same size might start around 2,000–3,000 lumens plus focused task lighting.
Do lumens add together?
Yes. If you use several bulbs, you can add their lumen values to estimate total output, although distribution and losses caused by each shade affect the real result.
Does a lampshade reduce lumens?
The bulb still emits its rated amount, but part of the light can be absorbed or redirected. That is why two lamps using the same bulb can illuminate differently.
Is it better to have too many lumens?
Not always. Excess light can be uncomfortable. A better solution is to combine several sources and, where possible, use dimming.
Before choosing bulbs, also review the difference between lumens, lux, kelvin and watts.
Once you have estimated the amount of light, distribute it between ceiling lamps and supporting light sources to avoid a flat lighting scheme.