Basic Lighting Calculation Tool

This tool helps you calculate lighting requirements for indoor spaces and provides optimal lighting layout suggestions based on room dimensions and lighting parameters using Lumen Method. Results are specifically calibrated for wide-beam (100°) LED fixtures to ensure alignment with Dialux software standards.

Calculation Objective

💡 Calculate Number of Luminaires

📊 Calculate Lux Level

Unit: mm Meters Feet

Space Dimensions (meters)

Length: Typical: 3-6m for rooms, 8-12m for classrooms Please enter a non-negative value Width: Typical: 3-5m for rooms, 6-8m for classrooms Please enter a non-negative value Height: Typical: 2.4-3m for residential, 3-4m for commercial Please enter a non-negative value

Lighting Requirements

(Select a room type to autofill the recommended lux value, or choose "Custom" to input your own)

Room Type: Target Illuminance (lux): Please enter a non-negative lux value

Light Specifications

(Choose a predefined light source type with preset lumen value, or select "Custom" to input your own)

Light Source:

Lumens: Typical: 800-1100 lm for 60W LED equivalent Please enter a non-negative lumen value

Installation Parameters

Mounting Height: Distance from floor to light fixture Please enter a non-negative value Working Plane Height: Typically 0.8m for desks, 0m for floor illumination Please enter a non-negative value

Surface Reflectance

Ceiling: 0.8 for white, 0.7 for light colors, 0.5 for dark Please enter a value between 0 and 1 Wall: 0.7 for light walls, 0.5 for medium, 0.3 for dark Please enter a value between 0 and 1 Floor: 0.2 for typical floors Please enter a value between 0 and 1

Quick Summary

Lighting Design Information

Calculation Method

This tool uses the Lumen Method formula calibrated to align with industry-standard Dialux software for accuracy:

N = ( E × A ) / ( F × UF × MF × 1.097 )

Where:

N = Number of luminaires
E = Required illuminance (lux)
A = Area (m²)
F = Luminous flux per luminaire (lumens)
UF = Utilization factor
MF = Maintenance factor
1.097 = Dialux alignment multiplier

Note: The calculation is specifically calibrated for modern LED luminaires with a wide 100-degree beam angle. This calibration ensures results are consistent with detailed simulation software, accounting for the complex light distribution of contemporary fixtures.

About Lux Levels

Lux (lx) is the SI unit of illuminance, measuring luminous flux per unit area. One lux is equal to one lumen per square meter.

Common Lux Requirements:

Corridors: 100-150 lux
Offices: 300-500 lux
Classrooms: 300-500 lux
Kitchens: 400-500 lux
Detailed Work: 750-1000 lux

Understanding Lumens

Lumens measure the total amount of visible light emitted by a source. Higher lumen values mean brighter lights.

Typical Lumen Values:

LED Bulb (60W equivalent): 800-1100 lumens
Fluorescent Tube (4ft): 2000-3000 lumens
Commercial LED Panel: 3000-4000 lumens

Lighting Layout Principles

Key Spacing Guidelines:

Spacing to Height Ratio (SHR): Typically 1.0-1.5 for uniform lighting
Wall Distance: Luminaires should be 1/3 to 1/2 of spacing from walls
Grid Patterns: Rectangular or square grids for uniform illumination
Avoid Shadows: Strategic placement to minimize shadows in work areas

Lighting Calculation Examples

Example 1: Office Lighting

Scenario: Lighting a 6m × 5m office space

Requirements: 400 lux for office work

Solution:

Area: 30 m²
LED panels (3000 lumens each)
Utilization factor: 0.65
Maintenance factor: 0.8
Calculation: (400 × 30) / (3000 × 0.65 × 0.8 × 1.097) = 7.0 → 7 luminaires
Layout: Appropriate grid based on room dimensions

Example 2: Classroom Lighting

Scenario: Lighting a 8m × 6m classroom

Requirements: 500 lux for reading and writing