Written by 8:53 pm The Guides

Light Bulb Facts: The Meaning of Lumens

We’ll show you how lumens are measured, an easy way to translate watts to lumens and why all …
SoCo Modern Socket Pendant with different light bulbs.
SoCo Modern Socket Pendant by Visual Comfort Modern

Lighting is all about lumens. Lumens tell you the brightness of a lighted bulb or integrated LED lighting fixture. If you’re used to thinking in wattage, you’re not alone.  Here are some guidelines to help you learn the new way to shop for light bulbs. We’ll show you how lumens are measured, an easy way to translate watts to lumens and why all these changes are a good thing.  

What is a lumen? How is it different from a watt?  

The definition of lumen is: “a unit of luminous flux in the International System of Units, that is equal to the amount of light given out through a solid angle by a source of one candela intensity radiating equally in all directions.”  

In short, lumens equal brightness. And watts do not. Not that watts are bad, but they measure energy use, not light output. With new, energy-efficient LED technology, we can no longer rely upon wattage to indicate how bright a bulb is. See how to measure lumens below:  

How many lumens do you need?

Use the chart above to determine exactly how many lumens are in a watt and vice versa. This should provide you with a good understanding of how bright 120 lumens is vs. a fixture with 5000 lumens. Additionally, you can use the color temperature chart to help you in choosing the best lighting for your application. 

How do I read the light bulb label?  

Changes in lighting regulations and technologies mean that there are new lighting terms to learn. For example, while we’ve previously looked to watts to learn a bulb’s brightness, that information is now presented in lumens. Newer bulbs have a Lighting Facts label that will give you all the details of a particular bulb:  

Lighting Facts.

Brightness: This is measured in lumens on the label. For example, 1100 lumens has brightness equivalent to a 75-watt bulb. This label is showing 820 lumens for a 60-watt incandescent bulb.

Estimated Yearly Cost: This is based on a set rate of usage each day. While your actual use may vary, the dollar amount noted will give you a good baseline.

Life: The overall expected life of the bulb, often in years. This is also based on estimated daily usage.

Light Appearance: Also known as color temperature, ranging from warm/yellow light to cool/blue light. (Warmer light in the 2700K range is what you’d expect from a standard 60W incandescent.) The K stands for Kelvin.

Energy Used: Here is wattage in its proper place. And with a shift to more energy-efficient light sources, you will not see the 40, 60, 75 or 100 watts like you used to. These days, you will more often see values in the 20s, teens or even single digits.

How do I choose an LED bulb?  

Look for the Energy STAR label.  

Especially in LEDs, the manufacturing quality of the bulb varies, with lesser bulbs not lasting as long as their better-built counterparts. As manufacturers rush to fill the market with LED bulbs in the wake of changing laws, watch out for cheap fixes—if it seems too good to be true, it likely is. Lighting experts currently recommend only buying Energy STAR-qualified LED light bulbs, as they must pass numerous quality tests to earn that designation.

Look at the bulb’s Color Rendering Index (CRI).  

The color rendering index shows how true colors are displayed under a light source. All old halogen/incandescent light bulbs have a CRI at or near 100, which is the maximum and roughly equivalent to full daylight. A good CRI for most indoor residential applications is 80 or above. A really good one is 90 or above, which is an excellent choice for bathroom vanity lights. Our LED bulbs and fixtures are 90 or above, with a few 80 CRI exceptions.

Check the color temperature.  

On light bulb labels, you can find the bulbs’ color temperature, measured on the Kelvin scale. The warmer light colors associated with incandescents are on the lower end of the scale. So, if that’s your preference, look for LEDs with light color temperatures in the 2700K to 3000K range. Pure white light hovers around 4000K, while cooler temperatures that simulate daylight are 5000K or higher.  

Forget watts…look for lumens.  

Lumens equal brightness; watts measure energy used. LEDs use much fewer watts than incandescents with the same brightness. As a rule, you’ll replace a standard 75W bulb with an energy-saving bulb of about 1100 lumens. On the low end, replace a 40W bulb with an LED bulb of about 450 lumens. Rely on new bulb labeling standards to show lumen output and help you choose the right brightness for your needs.

Everly Teardrop Pendants.
Everly Teardrop Pendant by Kichler

What are the new light bulb laws?  

The problem with traditional incandescent bulbs is that only 10% of their energy goes toward the production of light. The other 90% is heat—aka unused (essentially wasted) energy.  

Concerned about this significant waste of energy, the federal government set out to change regulations on light bulbs, requiring them to be more efficient. Since 2012, federal laws have gradually required the common types of light bulbs to be 25% more energy efficient. These federal regulations first applied to 100W incandescents (in 2012), 75W bulbs (in 2013) and 40-60W bulbs (in 2014).

As of 2023, incandescent bulbs will be phased out completely from the American market. Read more about those details here.

There are serious, measurable benefits to these changes. The U.S. Department of Energy estimates a collective household savings of $3 billion dollars nationwide—each year.

The LEDs now on the market are available in an amazing array of sizes, colors and shapes. And, yes, there are many that create that same wonderful, warm glow of the incandescent we’ve known and loved for a century.


Long-lasting, eco-friendly and super energy efficient…what’s not to love? LED bulbs are fast becoming the coolest light bulb of them all—literally, as they emit almost no heat and they thrive in cold locations.

  • Efficiency: At least 75% more efficient than standard incandescent 
  • Dimmable: Dimmable options and LED-compatible dimmers available 
  • Light Appearance: Wide variety of light colors and high color rendering (80-90 CRI) 
  • Average Life: 25,000+ hours (standard medium base) 
  • Suggested Uses: Great for outdoor, landscape, recessed, task and decorative lighting