As sellers of LED downlights, we know that downlight spacing and layout choices are a little complex. We aim to remove some of that confusion on this page with a series of easy-to-use downlight calculators.
See our lighting calculators page for a generalised (non-downlight) approach.
How Many LED Downlights Per Room?
One of our most common downlight questions is "how many downlights do I need?" To answer this question, you need to know three things:
- The intensity of light required (see our guide below)
- The size of the room or area.
- The light output of the downlights you would like to use.
The total light output of a downlight bulb or fitting is specified in lumens. Light intensity, on the other hand, is measured in lux.
This is where the following downlight calculator comes in. You can enter the lumens of your chosen LED downlight, the area of the space, and then estimate the number of fittings required. Our lighting calculator will display the average light intensity produced (lux).
To interpret these results, you need to understand what kind of lux levels would suit your property. Please see our summary guide below.
Downlight Levels (Lux) By Application
LED downlights are mostly used to achieve the 'General Lighting' or 'Task Lighting' brightness levels below. For other applications, you may be better off with a different type of LED light.
| Lux Level | General Guide | Specific Examples |
| less than 15 | Low-level Lighting | Outdoor pathway, street or security lighting. |
| 15 to 100 | Basic Lighting | For basic indoor & outdoor lighting, corridors, stairwells, storage areas, carparks. |
| 100 to 250 | General Lighting | Dining areas, workshops, indoor / outdoor entertainment, cafes, etc. |
| 250 to 600 | Task Lighting | Kitchen countertop, office work desk, classrooms, factory work, retail shops. |
| over 600 | Intense Lighting | Detailed desktop or assembly work |
Example Downlight Lumen & Lux Levels Using The Calculator
Using the above downlight calculator, here are some example results with our most popular LED downlights. See if you can replicate them or adjust them for your own lighting needs:
- Living and dining room: 45m² lit with 9 of our 90mm LED downlights at 800 lumens each for an average 160 Lux.
- A commercial office waiting area at 30m² lit with 5 of our 150mm LED downlights for an average 260 Lux.
- A home office or study of 10m² lit with 4 of our 120mm LED downlights for an average 400 Lux.
Please Note: the above is a rough calculation method only. It does not take into account other factors, such us:
- Light spill-over to surrounding rooms,
- The reflectivity of nearby surfaces (eg. dark walls and floors absorb light),
- The layout of the space (light levels will be more intense the closer you are to each light, and less intense as you move further away).
Downlight Spacing Calculator & Guide
With the above in mind, you can now also make some logical downlight spacing decisions.
LED Downlight Spacing
The following downlight spacing guidelines are depicted in the graphic below:
- Typical spacing between LED downlights is between 1.5m and 4m.
- For an LED downlight with a 100˚ beam angle, the light spread at floor level is about 2.4 times your ceiling height. Use our beam angle calculator to check other beam angles.
- Overlap of the lighting beam is required (as pictured below) for adequate lighting levels in most cases.
LED Downlight Spacing Calculator / Guide.
