Lighting Calculators

As LED lighting experts we know that lighting design can be complex.

On this page we aim to remove some of that complexity with a series of easy to use lighting calculators.

Beam Angle & Light Spread Calculator

First up, you'll notice that most LED lights have a specified beam angle. This is the angle that light is emitted from the light bulb or fitting. A common first question you may have is "how far will the light spread out?"

For this calculation, all you need to know is the beam angle and the distance from the light. This gives you an idea of the maximum area covered by a light.

You will soon notice that some beam angles can cover a vast area. But a 10W light and 100W light with the same beam angle are clearly not going to light up a space in the same way. This is why you need to go at least one step further into the realm of lux and lumens.

Lighting Calculator - How Many Lights Required

One of our most common lighting questions is "how many lights will I need?" To answer this question, you need to know three things:

  1. What you want to do in the space (ie. intensity of light required).
  2. What the size or area of the space is.
  3. The light output of the lights you would like to use.

The total light output of a light bulb or fitting is specified in lumens. You can find this specification for most LED lights - just be aware that low-quality brands (not the ones we sell!) can grossly exaggerate this figure.

Light intensity, on the other hand, is measured in lux. One lux is one lumen per square metre. Lux can be measured with a light meter, or it can be calculated in various ways as per the calculators on this page.

This is where our next lighting calculator comes in. You can enter the lumens of your chosen light bulb or fitting, the area of the space, and then estimate the number of fittings required. Our lighting calculator will then display the average light intensity produced (lux).

To interpret these results you need to understand what kind of lux levels would suit your space. Please see our summary guide below.

Light Levels (Lux) By Application

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, sport & recreation, cafes, etc.
250 to 600 Task Lighting Kitchen countertop, office work desk, classrooms, factory work, professional sport, retail shops.
over 600 Intense Lighting Detailed desktop or assembly work, competition grade indoor / outdoor sport.

Example Light Levels Using The Calculator

Using the above calculator with our most popular lights, here are some example results. See if you can replicate them or adjust them for your own lighting needs:

  • Living & Dining Room - 45m² lit with 8 of our LED downlights at 850 lumens each for an average 151 Lux.
  • Commercial Office - 100m² lit with 12 of our 1200 x 300 LED panel lights at 3,200 lumens each for an average 384 Lux.
  • Warehouse - 400m² lit with 5 of our LED High Bays at 16,000 lumens each for an average 200 Lux.

Please Note: the above is a rough calculation method only. By definition it cannot take into account other factors such us:

  • Light spill-over to surrounding areas,
  • Internal lighting reflectance (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).

Light Spacing Calculator

Putting together what you have learnt using these lighting calculators, you can now make some logical decisions about light spacing. More often than not, you will be guided by practical limitations here, such as:

  • Existing ceiling cut-out locations for LED downlights.
  • Location of roof trusses and beams for shed and workshop lighting.
  • Location of existing poles or other infrastructure for outdoor lighting.

For the vast majority of applications you will need a degree of overlap to provide adequate lighting. Here are some examples:

LED Downlight Spacing

 LED Downlight Spacing Calculator

LED Downlight Spacing Guide.

LED High Bay Warehouse Light Spacing

Warehouse Lighting Calculator

Warehouse Light Spacing Guide.

Two More Online Lighting Calculators

If you've got your head around the above two simplified lighting calculators, here are two more to play around with. The first calculator helps you understand the relationship between beam angle, lumens, distance, and lux.

For example, if you install an LED oyster light with 1,425 lumens and a 120˚ beam angle in your laundry, then you can expect about 202 lux at workbench height 1.5m from the ceiling.

Lumen to Lux Calculator

This next lighting calculator lets you work backwards from a desired lighting level to the number of lights required.

For example, for a target illuminance of 80 lux in a horse arena (20m x 40m) using a 19000 lumen 200W LED flood lights would need to install about 4 lights

Lighting Calculator

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