Lighting layout calculator

Calculate fixture count and verify illuminance levels

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The Lighting Layout Calculator helps lighting designers and electrical engineers determine the number of fixtures needed to achieve target illuminance levels in any space. Calculate fixture counts, verify lighting levels, and optimize layouts for energy efficiency.

Proper lighting design balances illuminance requirements with energy consumption and visual comfort. The calculator uses the lumen method, accounting for fixture efficiency, room geometry, and light loss factors to provide accurate fixture counts.

Enter room dimensions, target illuminance, and fixture specifications to calculate required fixture count and optimal spacing. The tool includes interactive layout visualization and supports multiple fixture types, helping you design effective lighting systems for offices, retail, industrial, and residential applications.

Features

Everything you need

Fixture count calculation using lumen method
Target illuminance by space type
Interactive 2D and 3D layout visualization
Multiple fixture type presets
Coefficient of utilization adjustments
Light loss factor calculations
Grid and staggered layout patterns

How it works

Simple workflow

1
Enter room dimensions and ceiling height
2
Select space type for target illuminance
3
Choose fixture type and specifications
4
Review calculated fixture count and spacing
5
Visualize layout in 2D and 3D views

Use cases

Built for real-world scenarios

Office lighting design

Design lighting layouts for office spaces to meet IES illuminance recommendations while minimizing energy use.

Retail lighting

Calculate fixture requirements for retail spaces with varying illuminance needs for different areas.

Energy code compliance

Verify lighting designs meet energy code power density limits while achieving required illuminance levels.

Renovation planning

Determine fixture counts and costs for lighting upgrades and retrofits.

FAQ

Frequently asked questions

Fixture count = (Area × Target Illuminance) ÷ (Lumens per Fixture × CU × LLF). CU (Coefficient of Utilization) accounts for room geometry, and LLF (Light Loss Factor) accounts for maintenance and depreciation.

IES recommendations: Offices 50 fc, Classrooms 50 fc, Retail 50-100 fc, Warehouses 20-30 fc, Corridors 10 fc, Parking 5 fc. Higher levels may be needed for detailed tasks.

CU accounts for how much light reaches the work plane based on room geometry, fixture distribution, and surface reflectances. Typical values range from 0.5-0.8 for most spaces.

Use high-efficiency LED fixtures, optimize fixture spacing, install occupancy sensors, and consider daylighting integration. The calculator helps balance illuminance with power density limits.

Have a suggestion?

We're always looking to improve our calculators. If you have ideas for new features, improvements, or found something that could work better, we'd love to hear from you.

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