Recessed LED lights have a magical quality about them and can be used for more than simply lighting a room. Careful placement and selection of the correct size your lights can highlight interesting architectural features or art pieces. However, the effect is only achieved if the lights are measured correctly and installed well.
When measuring the size of LED recessed lighting, it is important to measure only the diameter of that part that goes through the hole. It is also essential to measure the size of the recessed LED light correctly to ensure enough space on the ceiling’s reverse to accommodate it.
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How To Measure The Size Of Recessed Lighting
The difference between a recessed light installation, which looks professional and completes the look of a room, and one that is an eyesore, is measured in fractions of inches.
Two measurements of LED recessed lighting should be worked out before installation.
The Diameter Of The Unit
When you measure the diameter of the recessed light, it is important not to make the common mistake of measuring the fitting from edge to edge.
The distance that should be measured is the diameter of the back portion of the light, which is inserted into the light hole.
To do this correctly, remove the recessed light fitting’s trim or the LED module and measure the distance across the inside of the housing’s opening at the widest point.
The Depth (Height) Of The Unit
LED recessed lights are similar to icebergs in that much more is happening behind the ceiling than can be seen from the front. At the back of a recessed LED light is a cylinder (called a can) which contains the light fitting bulb, wiring, and sometimes a transformer.
When measuring up, you need to determine whether the unit has sufficient space behind the ceiling. In this regard, you need to check for (and aim to miss!) the following.
- Plumbing
- Electrical conducting
- Roof timbers
- Grandma’s bare feet if she occupies the room above 🙂
Recessed LED Light Dimensions
The relevant dimensions of the different recessed LED lights are summarized below. The can measurement is the size of the unit in the ceiling, hidden from view.
There are three sizes of recessed LED lights (cans):
- Standard cans are used in older models and take up substantial space in the ceiling
- Shallow cans are used in the more modern models
- Canless lights are generally available in smaller sizes
Recessed Lights Dimensions Table
In this table you’ll find common dimensions of typical recessed lights available in the market.
| Light Type | Housing Diameter | Hole Diameter | Lights that have a STANDARD Can Height | Lights that have a SHALLOW Can Height |
| 2 inch | 2 inches | 2 ⅜ inches | Canless | Canless |
| 3 inch | 3 inches | 3 ⅜ inches | Canless | Canless |
| 4 inch | 4 inches | 4 ⅜ inches | 5 ½ inches tall | 3 ½ inches tall |
| 5 inch | 5 inches | 5 ⅝ inches | 7 ½ inches tall | 5 ½ inches tall |
| 6 inch | 6 inches | 6 ⅜ inches | 7 ½ inches tall | 5 ½ inches tall |
| 7 inch | 7 inches | 8 ⅜ inches | 8 ½ inches tall | 8 ½ inches tall |
Dimensions Of LED Recessed Lights
Although these may vary from manufacturer to manufacturer, the fittings will invariably be close to the following rounded-up numbers.
- 2-inch and 3-inch recessed lights (less common)
- 4-inch recessed lights
- 5-inch recessed lights
- 6-inch recessed lights
- 8-inch recessed lights (less common)
Some LED recessed light fittings can be adjusted between two sizes. These lights show the range of possible adjustments on the packaging.
The uses and typical measurements of each recess LED lighting size are as follows.
2 Inch And 3 Inch Recessed Lights
With technological advances, smaller recessed LED downlights are becoming more viable and are increasing in popularity.
Normally, 2- and 3-inch recessed lighting is used to illuminate cabinets and display cases. They are also very effective when installed as accent lights in small spaces and highlight unique building features, art, and other areas of interest.
4 Inch Recessed Lights
4 Inch Recessed Lights are normally used to highlight a specific object or area (accent lighting) or to supplement the main lighting in a room for a task. This could provide additional lighting on a work area like a kitchen surface.
The typical luminescence of 4-inch LED recessed lighting can be compared to a 60W Incandescent globe.
- The cut-out diameter (size of the hole) for a typical 4-inch recessed light housing is 4-3/8 inches.
- The inside housing diameter measures approximately 4 inches when the trim is removed.
5 Inch Recessed Lights
Although few people select 5 Inch Recessed Lights for new builds or installations, if they are replacing older 5-inch units, it makes sense to keep the hole sizes standard.
The typical luminescence of 5-inch LED recessed lighting can be compared to an 80W Incandescent globe. Most 5 Inch Recessed Lights consume 15 watts. Most 6-inch light fittings are offered in 5-inch – 6-inch adjustment ranges.
- The cut-out diameter (size of the hole) for a typical 5-inch recessed light housing is 5-5/8 inches.
- The inside housing diameter measures approximately 5 inches when the trim is removed.
6 Inch Recessed Lights
The most commonly purchased LED recessed light size is 6 inches. These units provide a good spread of light and are ideal for large areas such as the bedroom, kitchen, and dining room.
The typical luminescence of 6-inch LED recessed lighting can be compared to an 80W Incandescent globe. Most 6 Inch Recessed Lights consume 15 watts.
- The cut-out diameter (size of the hole) for a typical 6-inch recessed light housing is 6-3/8 inches.
- The inside housing diameter measures approximately 6 inches when the trim is removed.
8 Inch Recessed Lights
Generally, 8-inch recessed lights are installed in commercial properties and less in private homes. The typical luminescence of 8-inch LED recessed lighting can be compared to a 100W Incandescent globe.
These lights typically use higher levels of power (watts) and produce more lumens than the smaller-sized recessed LED light fittings. Most 8 Inch Recessed Lights consume 18 – 20 watts. The disadvantages of 8-inch recessed Led light fittings are listed below:
- It means that they are less economical than the smaller-sized fittings
- The bright light they can produce can be harsh
They are, however, ideal for larger areas where good light is needed, such as a games room.
- The cut-out diameter (size of the hole) for a typical 8-inch recessed light housing is 8 – 1/8 inches
- When the trim is removed, the inside housing diameter measures approximately 8 inches
