What’s a Lumen?

The emergence of LEDs and energy savers have made choosing replacement bulbs a lot more tricky than it used to be. Being a cutting-edge technology, LEDs are constantly and rapidly becoming more efficient. One manufacturer may release a 5 watt LED which replaces a 40 watt bulb - and then a few months later, a different manufacturer will introduce a 5 watt LED which replaces a 60 watt bulb! This has made the Watt fairly redundant as a measurement of how bright a light bulb will be.


Watts don’t necessarily measure the brightness of a bulb, only the amount of electricity they use. With so many new bulbs giving out the same amount of light, but at a lower wattage, we need to compare bulbs by how much light they give out. From now on you will start seeing a ‘Lumen’ value listed on the side of light bulb boxes. Lumens are a measurement of how much light a bulb gives out in all directions.


You’ll still see the wattage shown on the box, but you shouldn’t use this to guess how bright the bulb will be. It’s just there to compare the amount of electricity used with the brightness of the bulb, which will be shown in Lumens - often shortened to ‘lm’.

While this will help consumers in the long run, it’s going to be a bit of a nightmare to get used to; we all knew where we stood with a 60 watt bulb! So here’s a table showing the brightness (in Lumens) of the more popular traditional filament bulbs. Learn these and you’ll always know where you stand!


Traditional Brightness in Lumens    
25W 230 lm    
40W 415 lm    
60W 710 lm    
100W 1340 lm    

Remember - the higher the Lumen, the brighter the bulb!