Buying Guide

CFL vs LED: How to Choose the Right Light Bulb


CFL bulbs are commonly characterized by their popular, spiral-shaped design and emit a softer glow. They contain small amounts mercury and can take a while to warm up to full brightness. As a result, they use minimal amounts of electricity.


LED bulbs are made using a light-emitting diode (LED). This is a solid-state semiconductor that emits light when a current passes through it. They great for hard-to-reach areas since they don't have to be changed as often.


Both CFL and LED bulbs are great for conserving energy. CFL bulbs are generally less expensive than LED options, but they have a shorter lifespan and must be carefully recycled due to their mercury content.


Tip: Energy savings ratings will vary from manufacturer to manufacturer. 

Light Bulb and Base Design

CFLs come in a variety of shapes, suited to different tasks and light fixtures. Dimmable light bulbs are also available. See the grid below for more details.  

Spiral bulb
Spiral bulb

Also known as “twister bulbs”

A basic CFL design with visible fluorescent tubes arranged in a spiral

These serve the same purpose as a traditional A-line/standard bulbs

Provides even light distribution

Ideal for lamps and light fixtures that hide the bulb behind a shade or covering

Triple tube bulb
Triple tube bulb

Compact bulb with visible fluorescent tubes

High light output

Takes up little space

Ideal for reading lamps

Bulb Base Type

There are five standard base sizes for CFLs: candelabra, intermediate, medium, G23 and GU24. Be sure to get a bulb with a base that matches your fixtures.


Slightly larger bulb base, used in chandeliers, light sconces and other small fixtures


Bulb base between the candelabra and medium sizes, commonly used in ceiling fans


Base design for standard light bulbs, used in most lamps and overhead light fixtures


A two-pin base that fits fixtures with a corresponding GU24 socket. GU24 is an energy-efficient system, designed to replace the conventional, screw-type socket and base design

G23 Bulb

A 2-pin base light bulb that is is ideal for use in kitchens, offices and other surface-mounted downlight or recessed fixtures.

Light Output & Power Consumption

CFLs are rated based on light output, which is closely related to power consumption. When selecting a bulb, consider its wattage and lumens.

Watts: Bulb manufacturers have traditionally used watts to represent light output, but wattage is actually a measure of power consumption, not brightness. Since CFLs consume less power, a CFL will have a much lower wattage than an incandescent bulb that produces the same amount of light.

Lumens: The standard unit of light output for bulbs is the lumen. A higher lumen number indicates a brighter bulb. A CFL and an incandescent bulb with the same lumen rating will produce the same amount of brightness.

Equivalent wattage: To make it easier to compare CFLs to incandescent bulbs, manufacturers generally provide an equivalent wattage rating for CFLs along with the lumens rating. The equivalent wattage tells you what type of incandescent bulb has the same light output as the CFL.

Lumens per watt: The standard measure of efficiency is the ratio of light output to power usage, represented as lumens per watt, or LPW. A higher LPW rating indicates greater energy efficiency and increased savings.

Bulb life: Bulb manufacturers usually provide an estimated bulb life for CFLs, listed in total hours. Quality CFLs have a bulb life rating of 10,000 hours or more. The exact bulb life for a CFL will vary depending on usage.

*Savings estimates are for lifetime of bulb, based on 3 hours of usage per day, at .12 cents per kilowatt hour

Light Output

250 lumens:

  • Incandescent Bulb-25 watts
  • CFL Equivalent-5 watts
  • Estimated Savings of CFL*-Up to $35

800 lumens:

  • Incandescent Bulb-60 watts
  • CFL Equivalent-13-16 watts
  • Estimated Savings of CFL*-Up to $55

1,600 lumens:

  • Incandescent Bulb-100 watts
  • CFL Equivalent-23-27 watts
  • Estimated Savings of CFL*-Up to $92

2,600 lumens:

  • Incandescent Bulb-150 watts
  • CFL Equivalent-42 watts
  • Estimated Savings of CFL*-Up to $129

* Savings estimates are for lifetime of bulb, based on 3 hours of usage per day, at .12 cents per kilowatt hour


CFL bulbs come in a range of color temperatures, making it easy to replace most incandescents with a CFL alternative.

While the first generation of CFLs had a characteristic blue tint, more recent designs re-create the warm glow of incandescent bulbs.

Bulb color temperature is rated in Kelvins. CFLs on the low end of the Kelvin scale emit a warmer, yellowish light, like a conventional incandescent bulb.

CFLs with higher Kelvin numbers emit a bluer light, like conventional fluorescent lights.

To maintain consistent light quality, use bulbs with the same color temperature in a room.

Color Types
Soft White - CFL Bulbs
Bright White - CFL Bulbs
Daylight - CFL Bulbs
Description Warm, yellowish glow Ideal for living rooms, dens and bedrooms Crisp, white light Ideal for work areas and kitchens Similar to natural sunlight Ideal for reading and detail-oriented work
Feature/Benefits 2,500 – 3,000k 3,500 – 4,100k 5,000 – 6,500k
How to Dispose of Light Bulbs

CFLs typically contain 4 mg of mercury. As long as the bulb is intact, the mercury is safely contained. Avoid contact with a broken bulb.

If you break a CFL, air out the room for 15 minutes. Approach the cleanup carefully, following the Environmental Protection Agency’s recommended procedure.

The EPA recommends that you bring old CFLs to qualified recyclers, rather than disposing of them in trash cans or curbside recycling bins.

You can bring old CFLs to The Home Depot for free recycling. Visit the Eco Options website to learn more.


If you’re concerned about the mercury content in CFLs, consider LED bulbs. One of many LED advantages is that they don’t contain mercury and do not have the same cleanup constraints. They are just as energy-efficient.