Best LED Downlights & Recessed Lighting (2026 Guide)

Recessed downlights are the dominant ceiling fixture in modern US homes — and one of the most commonly misunderstood. Using the wrong bulb type, wrong size, or wrong retrofit kit leads to wasted light, poor aesthetics, and shorter bulb life. This guide covers everything from basic can size identification to retrofit kit installation and the energy math on transitioning from halogen to LED.

Can Size: Start Here

Every recessed fixture has a nominal diameter that determines which bulbs and trim kits fit. In the US, most residential recessed cans are one of three sizes:

• 4" (102mm): Most common in hallways, closets, and as accent lights. Use PAR20, BR20, or a 4" retrofit kit.
• 5" (127mm): Common in housing built from 1980–2005. Use PAR30 or a 5" retrofit kit. Note: 5" and 6" don't interchange.
• 6" (152mm): The current standard for kitchens, living rooms, and general residential construction. Use BR30, PAR30, or a 6" retrofit kit.

If you're not sure what size your cans are: measure the opening diameter of the trim ring. The number in inches (approximately, it won't be exact) is your can size.

Retrofit Kits vs. Replacement Bulbs

You have two approaches to LEDing your recessed fixtures:

• Replacement bulbs (BR30, PAR30): Simply screw into the existing housing. Fast, cheap, reversible. Moderate efficiency — the fixture was designed for a different bulb form factor. OK for most residential use.
• Retrofit kits (integrated LED modules): Replace the entire trim assembly with a purpose-built LED module. Higher upfront cost, better optical efficiency, sleeker appearance, longer lifespan. Often dims more smoothly and to a lower percentage. For kitchens and main living areas, retrofit kits are worth the premium.

IC Rating and Air-Tightness

Before buying any downlight or retrofit, check two critical ratings:

• IC-Rated: If your ceiling has insulation above it (most homes do), you must use an IC-rated fixture. Non-IC rated fixtures can overheat when surrounded by insulation, creating a fire risk. Check the existing housing for an IC-AT label — if you're installing a retrofit kit, the kit itself must be IC-rated.
• Air-Tight (AT): Recessed fixtures without airtight gaskets allow conditioned air to leak into the attic, significantly increasing heating and cooling costs. Airtight-rated retrofit kits seal this gap. In cold climates, this can save $50–100+/year per 10 fixtures in energy costs alone.

Key Specs at a Glance

Our Top Picks for 2026

Downlight Spacing: Get the Math Right

• General rule: Space recessed lights 1.5–2× the ceiling height apart. An 8-foot ceiling → space fixtures 12–16 feet apart at maximum, but 4–6 feet apart for even overall coverage.
• Wall-wash spacing: For fixtures lighting adjacent walls, position them 18–24 inches from the wall and 24–30 inches apart from each other along the wall. Too close = hot spots; too far = scallop shadows.
• Kitchen rule: Position cans 18–24 inches from the cabinet face (toward the room center), aimed at the counter — not directly overhead where you stand.
• Avoid the "interrogation room" effect: Fixtures directly over seating create sharp shadows under facial features. Offset them 12–18 inches from where people typically sit or stand.

FAQ

What's the difference between a retrofit kit and a replacement bulb for recessed lights?

A replacement bulb (like a BR30) screws into your existing fixture socket and sits inside the original trim ring. A retrofit kit replaces the entire trim using a spring-clip mechanism that mounts to the inside of the existing housing — no tools, no rewiring. Retrofit kits are more efficient (light is aimed down, not in all directions), dim more smoothly, and last longer. They cost $15–25 each versus $5–10 for a BR30, but the performance difference is significant.

Can I mix 5" and 6" can lights in one room?

You can, but it's aesthetically inconsistent — the different hole sizes and trim diameter will be visible from below. If you're retrofitting an existing room with mixed sizes, choose retrofit kits that are "5/6 inch universal" — these clip into both sizes from the same module. They're common and available from most major LED retrofit brands.