Recessed Lighting 101: Choosing Downlights, Trims & Retrofits

Recessed lighting—often called "can lights" or "downlights"—tucks the fixture into the ceiling for a clean, uncluttered look. It's one of the most popular upgrades in modern homes, but the terminology around housings, trims, and retrofits trips up a lot of first-time buyers. Here's everything you need to plan a recessed layout with confidence.

The Three Building Blocks

Traditional recessed lighting has three parts: the housing (the metal can hidden above the ceiling), the trim (the visible ring or baffle), and the bulb. Modern LED retrofit modules and canless fixtures combine all three into a single slim unit—a big reason recessed lighting has gotten so much easier to install.

Choose Your Size

Recessed lights are sized by the diameter of the opening:

• 2–3 inch – small, accent-style lights for tight spaces and modern looks.
• 4 inch – great for task lighting over counters, hallways, and smaller rooms.
• 5–6 inch – the most common general-purpose size for living rooms, kitchens, and bedrooms.

Larger cans throw more light over a wider area; smaller cans give a tighter, more contemporary look and are easier to cluster. Browse options in our Recessed Lighting collection.

How Many Lights and How Far Apart?

A reliable starting rule: divide your ceiling height by two to get the spacing in feet. With an 8-foot ceiling, space lights about 4 feet apart. Keep the outer ring of lights roughly 2–3 feet from the walls so you light the room, not just the floor. For a kitchen or workspace, tighten the spacing for brighter, more even coverage; for ambient living-room light, you can spread them out.

Pick the Right Trim

Trims do more than finish the look—they shape the light:

• Baffle trim – ribbed interior reduces glare; the go-to for living spaces.
• Reflector trim – smooth, shiny interior maximizes brightness; good for kitchens.
• Adjustable / gimbal trim – tilts to aim light at art, walls, or features.
• Wall-wash trim – directs light across a wall to highlight texture or artwork.
• Shower / wet-rated trim – sealed lens for bathrooms and damp areas.

Get the Color Temperature Right

Recessed lights set the mood of a room, so color temperature matters. Use 2700K–3000K (warm) for living rooms and bedrooms, 3500K–4000K (neutral) for kitchens and bathrooms, and 5000K (daylight) for garages and workshops. Many modern LED downlights are selectable CCT—a small switch lets you pick the color at install time, so one product covers every room. Our Characteristics of Light guide explains how to choose.

Watch for IC Rating and Air-Tight

If a recessed light sits in a ceiling with insulation above it, you need an IC-rated (insulation-contact) fixture so it won't overheat. An air-tight (AT) rating also helps prevent drafts and energy loss between heated rooms and the attic—worth looking for in any exterior ceiling.

Retrofit vs. New Construction

Replacing existing cans? An LED retrofit module screws into the old socket and clips into the existing housing in minutes—no rewiring. Starting from scratch or remodeling? Choose new-construction housings (mounted before drywall) or remodel housings (installed through a finished ceiling). Slim canless LED units are increasingly popular because they fit shallow ceilings and install with a simple junction box.

Plan It Once, Enjoy It for Years

Map your spacing, pick a size and trim, and lock in your color temperature, and recessed lighting will transform a room. Explore fixtures and retrofits in our Recessed Lighting collection, and check the glossary if any term—IC-rating, CCT, gimbal—is new to you.