In the lighting industry, the “downlight size” usually refers to the cutout size in the ceiling. Common LED downlight cutout sizes include 2-inch, 3-inch, 4-inch, 5-inch, 6-inch, 8-inch, and 10-inch. However, the exact cutout dimensions may vary slightly depending on the manufacturer or brand. Generally, LED downlight size is proportional to its wattage: higher wattage requires better heat dissipation, which often results in a slightly larger fixture for the same type of downlight.
What Is LED Downlight Cutout Size?
When it comes to recessed LED downlights, the term cutout size refers to the diameter of the hole that needs to be cut in the ceiling or gypsum board. This measurement is critical, as it determines whether the downlight can fit securely into place.
It’s important to clarify that the cutout size is not the same as the fixture diameter. The fixture’s outer diameter is usually 10–20 mm larger than the cutout size. This extra margin allows the trim to cover the ceiling opening, creating a clean and seamless look.
For those who prefer ultra-slim or minimalist trim designs, precision becomes even more crucial. With trim widths as narrow as 6 mm, even a slight error in cutout measurement can result in visible gaps and installation failure.
Beyond installation, downlight size plays a key role in lighting performance and room aesthetics. The right size ensures balanced and comfortable illumination, while also enhancing the sense of space, depth, and visual appeal of the interior.
Standard LED Downlight Cutout Sizes
| Downlight size | Cutout size | Typical Wattage | Applicate |
| 2 inch | 55mm | 3-7W | Small corridors, wardrobes, display cabinets |
| 2.5 inch | 75-80mm | 5-10W | Small corridors, wardrobes, and display cabinets |
| 3 inch | 85-100mm | 7-15W | Bedrooms, kitchens, offices (general lighting) |
| 3.5 inch | 90-100mm | 10-20W | Bedrooms, kitchens, offices (general lighting) |
| 4 inch | 110-130mm | 15-25W | Living rooms, small retail shops, restaurants |
| 5 inch | 140-150mm | 20-40W | Living rooms, small retail shops, and restaurants |
| 6 inch | 160-180mm | 25W-50W | Small corridors, wardrobes, and display cabinets |
| 8 inch | 190-205mm | Large lobbies, shopping malls, and commercial areas | Airports, warehouses, industrial facilities |
This downlight size chart is just for reference. For some high-performance downlights, even smaller sizes can achieve higher wattages thanks to advanced heat dissipation designs. We also provide customized solutions—if you need non-standard downlights, feel free to contact our lighting experts.
How to Choose the Right Size?
When selecting a downlight size, several factors should be taken into account, including room area, ceiling height, interior style, and installation location.
- Based on room area: In general, the larger the room, the larger the downlight size should be. For example, a 10 m² room can use a downlight with a diameter of around 100 mm, while a 20 m² room may be better suited to a 150 mm downlight.
- Based on ceiling height: Rooms with higher ceilings can benefit from larger downlights to enhance the visual effect. Conversely, lower ceilings are better suited for smaller sizes to avoid a cramped feeling.
- Matching with interior design: Downlight size should match with the surrounding environment. For example, in a living room, the downlight size can be coordinated with the scale of furniture such as sofas and TV cabinets to create a cohesive atmosphere.
- Considering installation location: Placement also matters. Wall-mounted downlights usually work best with smaller sizes, while ceiling-mounted downlights can be slightly larger to provide better illumination.
Hello, customers
My name is Ricky Wang, I’m the business manager of GRNLED. I have been in LED lights industry for more than 10 year. Feel free to contact us. I’m happy to provide you the best service and products.
Email: info@grnled.com | WeChat: ledfixture
