Do you want warm lighting or cool tones? What will you be using the light for? Reading? General illumination? Ambiance? Are you looking for a cool, vintage aesthetic, or will any ol’ light bulb do? We’ll answer those questions and more in this guide to light bulbs.
Light Bulb Basics: Wattage and Lumens
Two things to consider when choosing a light bulb are watts and lumens. A light bulb’s wattage measures how much energy it uses. Lumens, on the other hand, measure a light bulb’s brightness—the higher the value, the brighter the light.
Back when nearly all light bulbs were incandescent (prior to 2012, when this style began to be phased out of the marketplace in favor of more energy-efficient options), the only thing you had to consider was a light bulb’s wattage.
That’s why most options nowadays include both lumens and a “wattage equivalent” number. For reference, a standard 100-watt bulb produces about 1600 lumens of light.
Note: All light bulbs are now required by the FTC to carry a standard label that details the bulb’s brightness (lumens), energy use and cost, lifespan, light temperature, and wattage. The National Resources Defense Council has a handy pamphlet explaining the new labels.
Types of Light Bulbs
There are four main types of light bulbs that are commonly used in homes:
Also known as Edison bulbs, incandescent bulbs are the traditional, filament light bulbs that most of us grew up with. Incandescent bulbs are incredibly energy inefficient—90 percent of the energy they use is turned into heat, not light—which both drives up electric bills and contributes to global warming (the more electricity used, the more carbon dioxide released into the atmosphere).
These old-fashioned light bulbs are being phased out in favor of more eco-friendly bulbs. Incandescent bulbs last only about a year with regular use, which is much shorter than any modern option.
Compact Fluorescent Bulbs (CFLs)
These are the light bulbs that look like a spiral tube. They’re about 50 to 80 percent more energy efficient than incandescent bulbs and last 7 to 9 years. The downside? CFLs take a while to “warm up” to their full brightness, and they contain mercury (the other bulbs listed here do not), so you have to be careful when disposing of them.
Light Emitting Diode Bulbs (LEDs)
LEDs are the most energy efficient and versatile light bulbs available. LED bulbs can last anywhere from 9 to 22 years (sometimes longer), and are available in a variety of styles, from traditional “light bulb” shape, to funkier, vintage-inspired designs.
LED light bulbs are often more expensive than other varieties but given their lengthy lifespan and low energy consumption rates, they’re usually the more budget-friendly choice in the long run.
Halogen bulbs are another type of filament-style bulb, similar to incandescent bulbs. They’re somewhat more energy efficient than incandescent bulbs but are nowhere close to CFLs or LEDs. Halogen bulbs usually only last about 1 to 3 years.
Light Bulb Temperature: Warm vs. Cool Lighting
When people describe the appearance of light as “warm” or “cool,” they’re referring to the light’s temperature. Temperature is measured on something called the Kelvin (K) scale, and most indoor lighting has a temperature between 2700K and 6500K.
Soft White/Warm White
At the lower end of the spectrum, from about 2700K to 3000K, you’ll find soft white lighting (also known as warm white). These are those cozy, yellowish tones that make a room feel welcoming and relaxing.
This is a great choice for bedrooms, living rooms, and other areas that you want to feel soft and inviting; it’s also perfect for table, floor, and pendant lamps. Light bulbs in this temperature range are most likely to replicate that old-school incandescent light feel.
Cool White/Bright White
Next is the 3100K-4500K range. Out of the yellow tones but not quite into the blue range, cool white lighting gives off a bright white light that makes for a more neutral atmosphere. This range is great for the kitchen, study, home office, garage, or anywhere you want light that’s vibrant but not harsh.
Light with a temperature of 4500K or more starts to get into the daylight territory. (For context, the sun at noon is between 5000K and 5500K). Light at this temperature has a bright, crisp, bluish appearance.
Daylight light shows off colors and details, and is great for reading, craft rooms and workshops, and accent lighting. Fun fact: Popular in workplaces, Daylight bulbs are thought to increase productivity.