What is Color Temperature?

Color Temperature is how warm or cool the light looks. Old incandescent bulbs were usually around 2700 Kelvin (K), which is a safe bet if you're not sure what color temperature you want.

What is High CRI?

CRI stands for Color Rendering Index, which is a measure of the quality of the light compared to sunlight. Sunlight has a CRI of 100. A CRI of 90 or above is considered high CRI.

For example, fluorescent bulbs have a low CRI with gaps in the color spectrum, whereas a high CRI bulb has a fuller color spectrum with fewer gaps.

Bulb Shapes Explained

The width of a bulb is measured in 1/8" increments. For example, a common A19 bulb indicates a diameter of 19/8" or 2-3/8 inches.

CFL or LED?

CFL - Compact Fluorescent Lamp. These are the curly looking bulbs and are considered obsolete. They contain Mercury and should be disposed of properly. Home Depot and Ace hardware stores will take them at no charge. They are also less efficient than LEDs, produce lower quality light, and burn out sooner.

LED - Light Emitting Diode. LEDs use about 85% less energy than an incandescent bulb, last 10-20 years, and produce rich quality light. Some older and cheap models don't perform as well, so be sure to look for "High CRI" or a CRI value of 90 or higher on the box to ensure high qualify light.

Bulb Bases Explained

There are many different bulb bases. E26 is the most common type.

How do I know what bulb to order?

The common, everyday, regular light bulb shape is A19 with an E26 base. For different kinds of bulbs, look for labels on the base of the bulb or fixture. If there are no labels, reference the Bulb Shapes and Bases explained above.

What do "Equivalent Brightness" and "Watt Equivalent" mean?

It is a measure of brightness, or Lumens.

We are used to describing a bulb's brightness in terms of Wattage, however Watts measure energy use, not brightness. Brightness is measured in Lumens.

For example, a 60 Watt Equivalent LED bulb will only use 9 Watts of energy, but it is just as bright as a 60 Watt incandescent bulb that wastes much of the energy as heat.