The short answer: multiply your room's floor area by 100 to 200 lumens per m² for bedrooms and hallways, 150 to 300 for living and dining rooms, and 300 to 500 for kitchens, bathrooms and home offices. A 4m x 4m living room needs about 2,400 to 4,800 lumens in total.
Watts used to tell you how bright a globe was. With LEDs they no longer do, because a 9W LED can be brighter than an old 60W globe. The number that tells you how much light you are buying is lumens. This guide explains what lumens are, how many each room needs, and what to buy to get there.
How many lumens do I need for each room?
Use the table to find your room, then multiply the lumens per m² by your floor area. The last column takes you to lights that suit that room.
| Room | Lumens per m² | 4m x 4m room | What to buy |
|---|---|---|---|
| Bedroom | 100 to 200 | 1,600 to 3,200 lm | Bedroom lighting |
| Hallway and stairs | 100 to 200 | 1,600 to 3,200 lm | Hallway lighting |
| Living room | 150 to 300 | 2,400 to 4,800 lm | Living room lighting |
| Dining room | 150 to 300 | 2,400 to 4,800 lm | Dining pendants |
| Kitchen | 300 to 500 | 4,800 to 8,000 lm | Kitchen lighting |
| Bathroom | 300 to 500 | 4,800 to 8,000 lm | Bathroom lighting |
| Home office | 300 to 500 | 4,800 to 8,000 lm | Study lighting |
| Laundry | 300 to 400 | 4,800 to 6,400 lm | LED battens |
| Garage | 200 to 400 | 3,200 to 6,400 lm | Garage lighting |
| Workshop | 500 to 800 | 8,000 to 12,800 lm | LED battens |
| Covered patio | 50 to 150 | 800 to 2,400 lm | Outdoor wall lights |
These figures are the total lumens from your fittings, so they already allow for some light being lost to shades, diffusers and dark corners. Treat them as a guide. If you are between two options, go brighter and add a dimmer.
How to work out lumens for your own room
Room length x room width x lumens per m² = total lumens
For a 3m x 4m bedroom at 150 lumens per m²:
3 x 4 = 12m², and 12 x 150 = 1,800 lumens
You can reach that total with any mix of lights. For this bedroom, you could use:
- One 1,800 lumen oyster light in the centre of the ceiling
- Four dimmable LED downlights, spaced evenly and turned down in the evening
- A pendant with a 1,000 lumen globe, plus two 400 lumen bedside lamps
Planning downlights? They are spaced for even coverage as well as brightness, so use the downlight calculator to get the quantity and layout.
What changes the number
- High ceilings: light weakens as it travels. Add 20 percent for ceilings over 2.7m and 40 percent over 3.3m.
- Dark walls and floors: dark surfaces absorb light instead of bouncing it around. Add 10 to 20 percent.
- Task areas: benches, desks and mirrors need more light than the rest of the room. Add a dedicated light, such as LED strip under kitchen cupboards, a vanity light at the mirror or a desk lamp.
- Age and preference: our eyes need more light as we get older. If the room is for reading, sewing or detailed work, aim for the top of the range.
What are lumens?
Lumens (lm) measure the total visible light a globe or fitting gives out. More lumens means more light. It is a standard unit, so an 800 lumen globe gives the same amount of light whichever brand makes it.
Lumens to watts: what replaces my old globe?
Watts measure the power a light uses, not the light it gives. If you still think in old incandescent wattages, this table shows the lumens to look for and roughly what an LED uses to produce them.
| Old incandescent | Lumens to look for | Typical LED |
|---|---|---|
| 25W | around 250 lm | 2W to 3W |
| 40W | around 470 lm | 4W to 5W |
| 60W | around 800 lm | 7W to 9W |
| 75W | around 1,100 lm | 10W to 12W |
| 100W | around 1,500 lm | 13W to 16W |
Efficiency is written as lumens per watt (lm/W). The higher the figure, the less power the light uses for the same brightness. Shop LED globes by lumens using the brightness filter.
What is lux?
Lux measures the light that lands on a surface. One lux is one lumen spread over one square metre. Lumens tell you how much light a fitting produces, and lux tells you how bright the floor, bench or desk ends up. Lighting designers work in lux. For choosing lights at home, lumens per m² is the simpler number and it is what the table above uses.
How many lumens for outdoor lights?
Outdoors, your eyes adjust to the dark, so you need far less light than inside. Instead of lighting the whole area, choose the right brightness for each fitting. As a rule of thumb:
| Outdoor light | Lumens per fitting | What to buy |
|---|---|---|
| Deck and step lights | 20 to 100 lm | Deck lights |
| Path and garden lights | 100 to 300 lm | Garden lights |
| Spike lights on trees and features | 200 to 500 lm | Spike lights |
| Wall lights at doors and patios | 400 to 800 lm | Outdoor wall lights |
| Driveway lights | 300 to 700 lm | Driveway lights |
| Sensor and security lights | 1,500 to 3,000 lm | Sensor lights |
| Flood lights for yards and courts | 3,000 lm and up | Flood lights |
Aim outdoor lights down and away from neighbours' windows. Several low output lights give a better result than one very bright one.
Dimmers give you room to move
A dimmer lets one room do two jobs: bright for cleaning and homework, soft for dinner and movies. That is why we suggest buying toward the top of the range and dimming down. Not every LED is dimmable, so check the listing, and match it with a compatible LED dimmer.
Lumens FAQs
How many lumens do I need per square metre?
Allow 100 to 200 lumens per m² for bedrooms and hallways, 150 to 300 for living and dining rooms, and 300 to 500 for kitchens, bathrooms and home offices.
How many lumens do I need for a living room?
Multiply the floor area by 150 to 300. A 4m x 4m living room needs about 2,400 to 4,800 lumens across all its lights.
How many lumens do I need for a kitchen?
Multiply the floor area by 300 to 500. A 3m x 4m kitchen needs about 3,600 to 6,000 lumens, plus task lighting over the benches.
Is 800 lumens bright enough for a room?
800 lumens is about the same as an old 60W globe. It is enough for a lamp, a small hallway or a toilet. Most bedrooms need two to four times that.
How many lumens is a 60 watt globe?
An old 60W incandescent globe gave about 800 lumens. An LED produces the same light using 7W to 9W.
Can a room have too many lumens?
Yes. Too much light causes glare and feels harsh, especially in bedrooms and living rooms. A dimmer fixes this without changing the lights.
Need a hand? Use the lumens calculator for your exact room, ask our lighting design team to plan it for free, or contact us with your room sizes.
