Watt is Watt? LED Light Bulb Terminology

When you start shopping for LED light bulbs, you'll notice that there is a lot of information about the product provided on the back of the package.

LED stands for “light emitting diode."

This information contains the specs you need to know to determine if its performance will meet or exceed your expectations.

If you're not familiar with the LED light bulb terminology, the information provided on the package might as well be a foreign language. This guide will take you through the standard terms to understand the product description.

What Is CCT in Lighting?

CCT stands for “correlated color temperature." It's the measurement used to describe how colors appear from a white light source. You'll see “warm" and “cool" tones described through this process, indicating that the illumination appears red, yellow, white, or blue.

As the CCT rating rises, the colors become cooler. This measurement is expressed in Kelvin, or K.

The warmest LED light bulbs tend to be in the 1700K to 2700K range. Once you go above that, you'll be in the cool or natural tones. Anything at 6000K or above is considered daylight.

Most homeowners prefer something in the 2700K to 3000K spectrum for the home. Businesses, especially warehouses and large buildings, typically install 4000K to 5000K products.

What Is CRI in Lighting?

CRI stands for “color rendering index." It represents the light quality produced while staying faithful to the colors it creates in a predictable environment.

Have you ever noticed how your skin looks a little yellow indoors, but it becomes a bit pale outside? That's because of the CRI differences between a warm color temperature from an incandescent lamp or LED and what the sun provides.

An ideal CRI is 100. That means you see the exact color as it is intended. Most LED bulbs provide a CRI rating that varies from 75 to about 95. A great CFL product might have one in the mid-80s.

What Are LED Lumens?

LED lumens are a standard measurement unit that describes the amount of light contained in a specific area. It's based on what the human eye perceives. If the rating is higher, you'll have a brighter light.

What makes the lumens rating unique is that you can use it to review different LED bulbs and brands or compare LED technology to CFLs, incandescent bulbs, and others.

Most rooms at home should have a lumens level of 1,000 to 2,000 from the installed lighting. Hallways tend to be a little darker, so an LED bulb providing 500 to 1,000 lumens is appropriate. Some people like something brighter for the bathroom, so 3,000 lumens could be okay there.

The best way to find how many lumens you'll need for a specific space is to measure the room. That means knowing the length and width before multiplying those figures together to get your square footage.

Once you have that figure, you can determine how many lumens are necessary to achieve your preferred brightness levels.

The basic calculation is to have 10 lumens for every square foot. That means a 200-square-foot living room would need 2,000 lumens or more to be comfortable.

Some spaces need more brightness than others because of the work you're doing. A garage or a shop might need 10,000 lumens. It would be appropriate for kitchen task lighting to have 8,000 lumens.

Rooms with darker walls and higher ceilings often need a higher lumens rating to ensure the expected results occur.

CRI vs. Lumens: What You Need to Know

CRI refers to how colors render under the LED light bulb installed. This rating applies at whatever lumens level is available from the product.

If you have two LED bulbs that each have an 85 CRI, but one is at 1,000 lumens and the other at 2,000 lumens, the colors will still look the same when you look at objects in that environment.

The lumens difference refers to the brightness levels offered by the LED lights.

Any Other Terms I Need to Know?

These three terms tend to be the ones that generate the most questions when shopping for LED light bulbs.

Some LED bulbs tell you a number, such as 5050 or 3528. This information indicates the size of the chips included in the product in millimeters. That means a 3528 is 3.5 mm by 2.8 mm. You can use this information to review the lumens rating in some products.

When you have this information available, it's easier to find the best LED lights for each environment. ​