What Size LED Downlight Do I Need?
\nStandard residential LED downlights are 4-inch or 6-inch diameter. Use 4-inch for small rooms, tight spacing, or accent lighting. Use 6-inch for larger rooms and primary ambient lighting. For 8ft ceilings, 4-inch at 800 lumens; for 9-10ft ceilings, 6-inch at 1100+ lumens. Space downlights 4-5ft apart in standard layouts.
\nDetailed Answers
\n\n4-inch downlights provide focused, directional light (narrow beam angle ~40°) — ideal for accent, task, and smaller rooms. 6-inch downlights provide wider, more diffuse light (beam angle ~60-90°) — better for ambient lighting in larger rooms. 4-inch suits 8ft ceilings, 6-inch suits 9ft+ ceilings.
\nStandard spacing: downlight diameter x 4 = spacing. For 4-inch downlights: space 4-5 ft apart. For 6-inch downlights: space 5-6 ft apart. Distance from walls: half the spacing distance (2-2.5 ft from wall for 4-inch, 2.5-3 ft for 6-inch).
\nRoom length (ft) ÷ spacing = lights per row. For a 12x14 ft room with 4-inch downlights spaced 4.5 ft: 3 rows of 3 = 9 lights minimum. Calculate total lumens needed (20lm/sqft × room sqft) and divide by per-fixture lumens to verify sufficiency.
\nYes. Use 6-inch for ambient lighting (center of room) and 4-inch for perimeter, accent, and task zones. This creates visual depth and prevents the 'grid ceiling' look. Keep all downlights at the same color temperature (3000K-3500K).
\n💡 Need recessed LED downlights, trim styles for your project?
\nBrowse certified LED products from verified suppliers at KS Import & Export.
\n Browse Products →\nSources & Standards
References: IES RP-16-17 (NEMA Size), NEC Article 410
Technical specifications verified against manufacturer datasheets and industry standards. Compare LED products side by side at lighting.compare2best.com.