How Bright Do You Need?
Remember how we said lumens measure ambient light output? That means the more lumens, an LED puts out, the more brightly lit a room will be. So the question you’ll need to answer is, how big is my room and how many lumens will I need to light it?
Here are some guideline figures, depending on the kind of surface you’re lighting:
20 lumens / sq ft for normal (floor) lighting.
30 lumens / sq ft for tables and countertops.
50 lumens / sq ft for reading and other tasks.
||Estimated lumens required
|15 x 20 ft (300 sq ft)
||Living room (floor)
|4 x 4 ft (16 sq ft)
|3 x 3 ft (9 sq ft)
||Bedside lamp (reading)
Of course you should combine lighting levels in rooms where you use different areas for different purposes. So if the living room example above has your 5×3 ft computer desk in one corner, the room (300 sq ft) will need around 6,000 lumens – with an additional 750 lumens for the desk (15 sq ft).
If walls, furniture or other surfaces are particularly dark colours, then you should increase the brightness of your lights. And your own preferences are important too – personally I prefer things a little bit dimmer, but if you like more light then you’ll want to add another 10 or 20% to the numbers above.