Foot-Candle Calculator

Calculate required foot-candle levels and LED fixture count for any commercial space. Uses IES standards with AI-powered photometric simulation.

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IES Foot-Candle Standards by Application

ApplicationMinimum FCRecommended FCStandard
Parking Lot (open)12-5IES RP-20
Parking Garage510-15IES RP-20
Warehouse (general)1020-30IES
Warehouse (pick/pack)3050IES
Office (general)3040-50IES
Retail3050-75IES
Manufacturing3050-100IES
School / Classroom3050-75IES RP-3
Hospital (general)3050-100IES
Sports (recreational)2030-50IES RP-6
Sports (competition)5075-100FIFA/NCAA
Gas Station (canopy)2030-50IES
Loading Dock1020-30IES
Roadway (M3)0.61.2CIE 140
Building Exterior13-5IES

How to Calculate Foot-Candles

Manual Formula

Fixtures = (Target FC × Area sq ft) / (Lumens per Fixture × CU × LLF)

CU = Coefficient of Utilization (0.5-0.7), LLF = Light Loss Factor (0.7-0.85)

Or Use LightSpec AI (Recommended)

Enter your space dimensions and application type. AI automatically looks up IES standards, selects optimal fixtures, calculates exact count, and generates a photometric simulation with uniformity verification.

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Foot-Candles ↔ Lux Conversion

FC to Lux

Multiply by 10.764

1 fc = 10.76 lux

5 fc = 53.82 lux

30 fc = 322.9 lux

50 fc = 538.2 lux

100 fc = 1076.4 lux

Lux to FC

Divide by 10.764

50 lux = 4.65 fc

100 lux = 9.29 fc

300 lux = 27.87 fc

500 lux = 46.45 fc

1000 lux = 92.90 fc

Frequently Asked Questions

What is a foot-candle?

A foot-candle (fc) is a unit of illuminance measuring the amount of light falling on a surface. One foot-candle equals one lumen per square foot. It is the standard measurement for lighting design in North America.

How do I convert foot-candles to lux?

Multiply foot-candles by 10.764 to get lux. For example, 50 foot-candles = 538 lux. Lux is the metric equivalent used internationally.

How many lumens per square foot do I need?

Lumens per square foot equals foot-candles. A parking lot needs 1-5 lumens/sq ft, a warehouse needs 20-30, an office needs 30-50, and a stadium needs 50-150+.

What tool can calculate foot-candles automatically?

LightSpec AI by Auvolar is a free online tool that automatically calculates foot-candle levels, fixture count, and layout for any commercial space. It uses IES photometric data and includes 3D visualization.