Looking at Lumens

Looking at Lumens

By Michael Morrison on Tue 23 November 2021

What are lumens? How do lumens effect light? Does more lumens mean more light? How can you convert lumens to watts? All these questions and more answered in our short yet sweet write up. 

Taking a look at lumens

Simply put, Lumens are the measure of light from a source, e.g. a bulb. The higher the lumens, the brighter the bulb will be, and the lower the lumens, the dimmer the bulb. Traditionally most people would have looked at the wattage of a bulb to determine how bright it was going to be, for instance, a 60W bulb would be brighter than a 40W bulb, but not as bright as a 100W bulb. However, with the advancements in recent years from LED efficiencies, as seen in our post ‘Watt’s it all about’, this just doesn’t really translate anymore. Therefore the more accurate way to know what you’re getting is by looking at the lumen count. 

Lumens, not watts, what to look for?

So really what you want to know is how bright do you want an area to be? Just think, is it an office space where everything needs to be clean and clear, but not so bright that it can hurt the eyes of staff, or a retail space where you want to throw the best light on the goods, or is it to be a residential or hospitality space where the lighting can help set the mood and becomes more welcoming? Once we know what the area is and how bright we will need it to be, then we think about the bulbs themselves. When looking at lumens, it really is as simple as the higher the lumens number, the brighter the bulb, a bit like back in the day, the higher the watts, the brighter the bulb.

If you’re used to the old style of working with the watts of a bulb, consider this…

A 100W incandescent bulb will produce around 1600 lumens.

A 75W incandescent bulb will produce around 1100 lumens.

A 60W incandescent bulb will produce around 800 lumens.

A 40W incandescent bulb will produce around 450 lumens.

Once you have that in mind then it should be really simple to think about the lumens you want for your room/space application. Below is a handy table that gives you an idea of what an old incandescent bulb would translate to in some of the more modern replacements. 



Incandescent Bulb wattage

Gives out roughly this many lumens


(more efficient incandescent)


(more efficient)


(most efficient)

100 W


up to 72 W

up to 26 W

up to 14 W

75 W


up to 53 W

up to 23 W

up to 12 W

60 W


up to 43 W

up to 15 W

up to 8 W

40 W


up to 29 W

up to 11 W

up to 6 W

Here at Lamp Source, we are more than happy to help you get the right bulb for your use with your building or space. Feel free to reach out to our Sales Team and ask anything you need.