A couple of days ago, the 60-watt incandescent bulb I’m using on my working desk burned out and I wanted to replace it with an LED bulb but really wanted to nail the brightness. So I saw this as the perfect opportunity to write a helpful guide explaining the differences between watts and lumens and how these affect brightness.
Most 60-watt incandescent bulbs produce about 800 lumens. Depending on the type of filament and the rated lifetime, the brightness of the bulb can range from 500 to 900 lumens. The equivalent LED bulb needs about 8–10 watts to produce 800 lumens.
This is because wattage measures the amount of energy consumed by the bulb (which is no longer good enough to estimate brightness), while lumens specifically measure brightness. Therefore, the lumen output of a bulb depends on the type of the bulb, as some are more energy-efficient.
See the table below for a complete comparison of watts and lumens for each bulb type!
Incandescent bulbs produce only about 15 lumens per watt but LED bulbs produce about 80 lumens per watt, making them up to six times more energy-efficient! This is because LEDs emit almost no heat but up to 90% of an incandescent bulb’s energy is released as heat.
How Many Watts Does Each Bulb Use?
I made this simple table to help you figure out how to replace an old bulb and make sure that the brightness does not change. Look at the wattage of your current bulb and choose a new one from that same row.
Keep in mind that the above are estimates and do vary depending on the manufacturer. Thankfully, all modern packages state both the wattage and lumen output, so just check that before you make a purchase to be certain.
Using the table above, you can see how different bulbs require different energy inputs to achieve the same brightness. Keep in mind that, in theory, brightness does not affect the color temperature, i.e., how warm (yellowish) or cool (blueish) the light is.
And I’m saying in theory because, in practice, we perceive cool light as brighter, even though the bulbs might give the same lumens.
How Many Lumens Per Watt Does Each Bulb Give?
In case the above table does not cover your lumen requirements, here is a simple conversion table showing how many lumens one watt gives off for each bulb (meaning lumens per watt). Lower lumens per watt means higher energy consumption and less efficiency.
|Bulb||Lumens per watt|
These ranges are quite large because the relationship between lumens and watts is not linear. This is especially true for values on either side of the spectrum (very low or very high brightness). Also, the brightness-to-consumption ratio depends a lot on the manufacturer.
Even so, it is clear that LED bulbs are by far the most energy-efficient. Combined with the fact that they typically are the longest-lasting (more than a decade), LED bulbs can cut down your lighting expenses by a non-negligible amount!
Lower energy consumption and longer lifespan are the two main advantages of LED bulbs. Their versatility in color and brightness adjustments makes them an excellent choice for most spaces.
What Is The Equivalent Wattage For LED Bulbs?
For an even simpler way to figure out the watt equivalency of different bulbs, check out this table. I have compiled this information based on the most common wattage used in households.
|LED watts||Incandescent watts||Halogen watts||CFL watts|
So for example, a 60-watt incandescent bulb can be replaced by a 10-watt LED bulb. However, as we said previously, checking out the lumen output of each bulb is more accurate for ensuring the same brightness.
What To Pay Attention To When Replacing An Old Bulb
Now that you know how many watts you need for your desired brightness, follow this list to make sure that your new bulb is as good as the old one, or even better.
- Check the voltage. If the fixture has a lower voltage than your bulb, the bulb might not light up. If however the bulb has a lower voltage than the power supply, this might burn the bulb instantly or permanently damage the fixture. All of North America (including the U.S.) and half of South America, require 120 V of electrical settings. On the contrary, Europe, Asia, Australia, and most of Africa require 240 V. A small difference of about 10 V should be fine (aiming for higher voltage in the bulb for better handling of voltage surges) but more than that might be hazardous.
- Check the wattage. Double-check your specs to avoid any surprises on the bill.
- Check the base. More than a few times I’ve bought a bulb that just didn’t fit my fixture (oh yes). Never force the bulb into the base of the fixture – it should fit easily!
- Check the bulb shape. The shape of the bulb is an important part of the overall aesthetics of your lighting plan. Although subjective, make sure you like the look of it. Also, make sure that it fits your fixture space-wise. For example, a tight lamp shade might not allow big round bulbs but only work with candle-like shapes.
How Bright Are 800 Lumens?
A bulb of 800 lumens would be fine for most everyday applications but this depends on where you want to use it.
For example, if this bulb is used as the main ambient light in your bedroom, it would create a nice atmosphere and you would easily be able to find your socks, but reading might be a bit difficult. I would suggest an extra light source for that.
Reading in bed would fall into the “task lighting” category, and would require a bedside lamp of about 250 lumens. More than that might interfere with your sleep cycle.
Similarly, 800 lumens for kitchen under-cabinet light would probably be too much. You want to look into the 300-400 lumen range. However, a 50 sq. ft. bathroom would be sufficiently lit with 800 lumens of ambient lighting.
To put it into perspective, a 180 sq. ft. (17 sq. m.) room is typically sufficiently lit with 1800 to 3600 lumens. So we would need about 3-4 LED bulbs of 800 lumens each to properly light up this space.
How Much Money Do You Save With LED Bulbs?
Just to put into perspective how much more efficient LED bulbs are compared to incandescent, 150 watts of an incandescent produces about 2200 lumens and can be replaced by a LED bulb of 21 watts. However, 150 watts of a LED bulb could produce up to 15000–20000 lumens!
Considering that the average residential electricity rate in the U.S. is $0.16 per kilowatt-hour (kWh), one incandescent bulb of 60 watts running for 8 hours a day costs about $2.3 every month. A 10-watt LED bulb would produce the same brightness but would cost only $0.38 – six times (or $1.92) cheaper!
From an economic standpoint, it makes sense to replace old and energy-inefficient bulbs with LEDs, as they cover their cost in less than one month.