While LEDs may have revolutionised lots about light, they have made choosing a bulb a lot more challenging. Because they are changing all the time, and becoming more efficient, the available range increases all the time.
One manufacturer can create a 5 watt LED as a replacement for a 40 watt traditional bulb; another manufacturer may create a 5 watt LED bulb to replace a 60 watt bulb. In other words, it’s not so easy to use wattage to tell how bright a lamp is.
Watts do not actually tell you how bright a bulb is; they tell you how much electricity it uses. Because there are lots of bulbs emitting the same amount of light, just at lower wattages, bulbs should really be compared by the amount of light they emit. To do this, you need to look at the “lumen” value assigned to the bulb.
The lumen is a measurement of the light given by a light bulb, in all directions.
Even though the wattage is still a visible value, it won’t tell you how bright the bulb will be. You can however use it compare bulb brightness with power consumption.
A traditional 25W bulb has a light output of 230 lm
A traditional 40W bulb has a light output of 415 lm
A traditional 60W bulb has a light output of 710 lm
A traditional 100W bulb has a light output of 1340 lm.
The more lumens, the brighter the bulb will be.