Custom HTML

Which High Bay Light Models and Quantities You Need for Different Sized Spaces.

The required High Bay light models and quantities for different sizes and purposes of spaces.

Your lighting needs depend on the size and purpose of your space. First, let's determine the purpose of your space because it dictates the required illuminance (lux) per square meter. Different purposes need different amounts of light. Illuminance (lux) is the amount of light received per square meter, measured in lux (lx). Specifically, it indicates how many lumens (units of light) hit each square meter. For example, 1 lux means 1 lumen per square meter. This concept helps describe brightness levels to ensure the light source meets the specific needs of a space.

Different spaces require varying levels of illuminance depending on their use and the activities conducted within them. Here are some common locations and their recommended illuminance levels, measured in foot-candles (FC) and lux (1 FC is approximately equal to 10.76 lux):

  1. Residential and Office Spaces

    • Bedroom: 10-20 FC (100-200 lux)
    • Living Room: 10-20 FC (100-200 lux)
    • Kitchen: 30-50 FC (300-500 lux)
    • Study or Desk Area: 50-75 FC (500-750 lux)
    • Bathroom: 30-50 FC (300-500 lux)
  2. Commercial Spaces

    • Office Work Area: 30-50 FC (300-500 lux)
    • Conference Room: 30-50 FC (300-500 lux)
    • Reception Area: 20-30 FC (200-300 lux)
    • Retail Stores: 50-100 FC (500-1000 lux)
    • Restaurants: 5-10 FC (50-100 lux)
    • Warehouse and Storage Areas: 10-30 FC (100-300 lux)
  3. Industrial and Manufacturing

    • General Manufacturing Areas: 30-50 FC (300-500 lux)
    • Fine Work or Inspection Areas: 50-100 FC (500-1000 lux)
    • Assembly Line: 50-75 FC (500-750 lux)
  4. Educational and Healthcare

    • Classrooms: 30-50 FC (300-500 lux)
    • Laboratories: 50-100 FC (500-1000 lux)
    • Hospital Wards: 20-30 FC (200-300 lux)
    • Operating Rooms: 100-200 FC (1000-2000 lux)
  5. Outdoor

    • Parking Lots: 5-10 FC (50-100 lux)
    • Sidewalks and Walkways: 10-20 FC (100-200 lux)
    • Sports Fields: 30-100 FC (300-1000 lux)

These values are based on general standards and recommendations and can be adjusted according to specific requirements and regulations.

After understanding the required illuminance for different spaces, you can calculate the total illuminance needed for your space to match its purpose.


How to Calculate Illuminance per Square Meter:

  1. Determine the Total Luminous Flux (Lumens) of the Light: This is the total light output from the light fixture, usually specified in the product specifications. Note: If one light isn't enough, you can use multiple lights to achieve the required total luminous flux.

  2. Calculate the Total Area (Square Meters) of the Space: This is the floor area or the area that needs lighting, not the volume.

  3. Calculate the Illuminance (FC) per Square Meter: Divide the total luminous flux by the total area to get the illuminance per square meter.

Illuminance (lux)=Total Luminous Flux (lumens)Total Area (square meters)




If you have a venue is 50ft*100ft area, want to do studio (50fc), you fancy 200W adjustable series UFO high bay light. But you don't know how many will be needed to meet your site usage requirements. So let's apply the formula now. It is very simple to calculate the IES software calculation results. The calculation formula is as follows.

This means that if you know the area and purpose of your space but are unsure about the number and type of lights you need, you might use the following formula to calculate the number of lights required:

Required Number of Lights=Illuminance (Lux)×Area / Lumen Output per Light (Model)

Sure, let's calculate the number of lights needed for your space using the provided formula.

Number of lamps required = (50ft*100ft*50fc) /28000=8.93 unit

So, you would need approximately 9-10 200W high bay lights to achieve 500 lux(50 fc) in a store with an area of 50 ft by 100 ft.


The actual situation is arranged according to the distance between the lamps, and only 9-10 lamps are used.


Key Factors Contributing to the Discrepancy:

  1. Inverse Square Law:

    • The intensity of light decreases with the square of the distance from the source. As the lights are installed higher, the light spreads over a larger area, reducing the illuminance.
  2. Beam Angle:

    • The beam angle of the light affects how the light is distributed. A wider beam angle spreads the light over a larger area, reducing the illuminance per unit area. High bay lights typically come with different beam angles, such as 120 degrees or 90 degrees, which affect light distribution differently.
  3. Reflection and Absorption:

    • The reflectivity of surfaces in the space (walls, ceiling) affects light distribution. High reflectivity can increase the overall illuminance, while absorbent materials can decrease it.
  4. Uniformity Requirements:

    • Lighting design software ensures uniform lighting throughout the space, avoiding areas that are too bright or too dim. This often requires more lights to achieve even distribution.
  5. Obstructions and Obstacles:

    • In a warehouse, shelves and other obstructions can block light. Additional lights are needed to compensate for these blocked areas and ensure adequate lighting.
  6. Maintenance Factor:

    • Lighting design software accounts for the decrease in light output over time and the need for maintenance. This is factored into the initial design to ensure that the lighting remains adequate over the lifetime of the installation.


high bay light Installation height reference drawing


1 thought on “Which High Bay Light Models and Quantities You Need for Different Sized Spaces.


Very useful

May 22, 2024 at 10:51am

Leave a comment

Your email address will not be published. Required fields are marked *

Please note, comments must be approved before they are published