Understanding LED Lightbulbs
Today's LEDs can take your home's illumination to a higher level, but there is a learning curve. Here's how to make the most of these energy-saving bulbs.
Once upon a time, buying a lightbulb meant choosing an incandescent one of between 25 and 100 watts, depending on how bright you wanted the light to be and the fixture you were putting it in. You might go to a specialty lighting store to find fancy candle-style bulbs for a chandelier or a floodlight for your porch, but your choices were pretty limited, and so was the need to understand lighting minutiae.
But that’s changed. The introduction of energy-saving LEDs (which use 75 percent less electricity than incandescents), along with the 2022 Department of Energy guidelines to phase out incandescent technology, mean we all have to learn a new vocabulary around purchasing lightbulbs. Here’s what to know.
The New Basics of Bulbs
The key difference between the incandescent bulb Thomas Edison invented in the late 1800s and today’s LED bulb is how each converts energy into light. Think of incandescent technology this way: When you put a piece of metal into a bonfire, the fire makes it glow—and the filament inside an incandescent bulb does much the same thing. Exposure to electric current makes it glow, creating light. It also gets very hot. In fact, nearly 90 percent of its energy is wasted as heat, not light.
The guts of an LED bulb are more akin to a grouping of tiny electronic semiconductors illuminated by the movement of electrons across their surface. Your flat-screen TV consists of thousands of mini LEDs. These throw off almost no heat: About 90 percent of their energy gets converted to light. That means a 60-watt incandescent can be replaced by an LED that uses less than 10 watts, which is great for your electric bill. But if you want attractive lighting with the familiar look of incandescent bulbs, you’ll need to shop in a slightly different way. And that starts with the label. Here’s where you’ll find important information about the brightness and quality of light the bulb produces.
Begin With Brightness
Many of us chose incandescent bulbs by wattage and thought of the number of watts as an indication of brightness. A 100-watt incandescent bulb looks much brighter than a 40-watt incandescent. Wattage is actually a metric of energy, and the light intensity that energy produces is measured in lumens. That’s the term to look for on an LED package: The higher the lumen count, the brighter the bulb. To put things in perspective, a 100-watt incandescent bulb puts out 1,600 lumens, so when shopping for a replacement LED you want that lumen count. The chart below shows the rough equivalents between lumens and watts, but many LED packages now contain phrases such as "60W replacement" to make the conversion simpler.
Think About the Effect You Want
You’ve probably noticed that some lighting sources look "warm" (more yellow or amber) or "cool" (more blue or gray). Incandescent lightbulb packages often described these styles as "soft white" or "daylight." You might see those same terms on LED lightbulb packages today. But Terry McGowan, a lighting engineer who worked for GE on major lighting projects and is now director of engineering for the American Lighting Association, says there’s a better way to get the effect you want.
Another thing to know: Some LEDs can make colors look "off." McGowan explains that lower-quality LEDs can make everything in a room look flat, so vibrant colors appear much duller than they actually are. Better LEDs have what’s called a higher Color Rendering Index (CRI), indicated on a scale from 1 to 100, which measures how accurately a bulb illuminates. "Go with 90 or 95 CRI if you can find it," says Marty Schmidt, the brand director for System 7, a Boston-based home lighting company. Not all LED packages note the bulb’s CRI number, McGowan says, so you may have to search for the product online to get that information. Higher CRI bulbs may cost a little more because they require more complex technology to reach those higher levels of accuracy.
Finally, decide whether you want dimmable bulbs. Not all LEDs dim well. Unlike incandescents, which naturally emit a warm, amber light when lowered, LEDs "can look both kind of gray and also bluer," McGowan says. So check for the word "dimmable" on the label, and shop for what’s called "dim-to-warm," which indicates an LED made to emulate that incandescent yellow-orange candlelight-type glow. One caveat: Some LEDs work only with certain kinds of dimmers. (The manufacturer’s website should have that information.) Don’t know what dimmer you already have? You could buy a dim-to-warm LED and try it out. Keep your receipt: If it doesn’t dim well or makes a noise, you may have to return it and try again.
Look for Long-Lasting Performance
According to the Department of Energy, LEDs should last up to 25 times longer than equivalent incandescents. But your mileage may vary. McGowan suggests reading the warranty of any bulb. For instance, the GE Sunfilled bulbs shown below at left are labeled as having 13.7 years of life, but that’s based on 3 hours of use per day. The warranty they carry is for three years, not 13. WiZ smart bulbs—$11 each—also have a three-year warranty.
One bonus: Depending on where you live, your utility company may offer in-store or coupon discounts on bulbs through the federal government’s Energy Star system. You can find these offers on energystar.gov and also filter the bulbs you find for lumens, CRI, and dimmability.
As for disposal, LEDs should be recycled. Some stores, like Home Depot, as well as local recycling centers, have programs in place. Find more by searching for "LED lightbulb" on earth911.com.
As your eyes age, the muscles that control the pupils get weaker and the lenses get thicker. That can increase the need for brighter light.
Some Good LED Lightbulb Choices
The GE, Philips, and Cree Lighting bulbs shown below check the boxes for high-quality light, as explained by the experts we consulted. Shopping tip: For consistent color temperature and CRI (illumination), it’s best to stick with one brand throughout your whole house. Also, some LEDs have a dual-prong socket. You can buy inexpensive adapters to help fit your fixtures.
Soft, Warm Light for Table and Floor Lamps
GE 60W Sunfilled A19 Soft White
840 Lumens, Dimmable, 2700K, 97 CRI
$11 at Target
Tunable Smart Bulb
Philips 60-Watt Equivalent A19 LED Smart Wi-Fi Color Changing Smart Light Bulb powered by WiZ with Bluetooth
800 Lumens, 2200-6500K, 90 CRI
$13 at Walmart, $11 at Home Depot
Bright, Cool Light for Work Areas
Cree Lighting A19 100W Equivalent LED
1600 Lumens, Dimmable, 5000K, 90+ CRI
$9 at Amazon
Photo: Scott Meadows/Consumer Reports Photo: Scott Meadows/Consumer Reports
Editor’s Note: This article also appeared in the January 2024 issue of Consumer Reports magazine.
