Foot Candle Calculator
Calculate the lighting requirements for any space using IES standards
1Space & Lighting Details
= 538 lux
Length
Width
Check your fixture specifications for lumen output
Advanced Settings
2Lighting Requirements
21
Fixtures Needed
@ 5,000 lumens each
Total Lumens Required
100,840 lm
Total Floor Area
1,200 ft²
Estimated Wattage
~1,008 W
Lux Equivalent
538 lux
Lumen Method Formula
Lumens = (FC × Area) ÷ (CU × LLF)
FC = Target foot-candles
Area = Room area in square feet
CU = Coefficient of Utilization (0.5-0.9)
LLF = Light Loss Factor (0.7-0.9)
IES Lighting Standards
Understanding Foot-Candles in Lighting Design
Foot-candles measure the amount of light that reaches a surface, making them essential for proper lighting design. Different tasks and spaces require different light levels - a warehouse needs less light than a surgical suite. Using the correct foot-candle levels ensures safety, productivity, and energy efficiency.
How the Lumen Method Works
This calculator uses the lumen method, the standard approach for calculating indoor lighting. It considers your target illuminance, room size, fixture efficiency (CU), and expected light degradation over time (LLF) to determine how many lumens and fixtures you need.
Lighting Design Tips
- •For task lighting (desks, workbenches), aim for 50-75 foot-candles; ambient lighting can be lower
- •Higher ceilings require more lumens - adjust the CU factor downward for spaces over 12 feet
- •LED fixtures maintain their output better than fluorescent, so you can use a higher LLF (0.9 vs 0.7)
- •Consider using multiple smaller fixtures for more even light distribution rather than fewer large ones