What is a beam angle in LED lighting?

Beam angle is the angle at which light spreads from a fixture. A narrow beam angle (15 to 30 degrees) creates a concentrated spot, while a wide beam angle (60 to 120 degrees) produces a broad flood of light. The beam angle determines how large the light pool will be at any given distance from the fixture.

How do I calculate beam spread from beam angle?

Beam diameter equals 2 multiplied by the distance multiplied by the tangent of half the beam angle. For example, a 60-degree beam at 8 feet produces a beam diameter of approximately 9.2 feet. Our calculator above performs this calculation instantly for any combination of beam angle and mounting height.

What beam angle do I need for a kitchen?

For general kitchen lighting, use a beam angle of 60 to 90 degrees for even illumination. For task lighting over countertops, a narrower 25 to 40 degree beam angle focuses light where you need it. For under-cabinet lighting, 120-degree wide flood provides uniform coverage across the countertop surface.

What is the difference between spot and flood beam angles?

Spot beams are 10 to 30 degrees and produce a tight, concentrated circle of light ideal for highlighting specific objects or architectural features. Flood beams are 40 to 120 degrees and spread light broadly for general illumination. Narrow flood (40 to 60 degrees) bridges the gap, offering focused but wider coverage.

How does mounting height affect beam spread?

Beam diameter increases linearly with distance. Doubling the mounting height doubles the beam diameter at the surface. For example, a 60-degree beam produces a 4.6-foot diameter at 4 feet but a 9.2-foot diameter at 8 feet. This is why ceiling height directly influences which beam angle you should choose.

What beam angle is best for wall washing?

For wall washing, use a beam angle of 90 to 120 degrees with fixtures placed 2 to 3 feet from the wall. The wide beam angle ensures even coverage across the wall surface without hot spots. For wall grazing on textured surfaces, a narrower 30 to 45 degree beam placed closer to the wall creates dramatic shadows that highlight texture.

Reference Standard

IES Recommended Light Levels

Complete reference table of IES (Illuminating Engineering Society) recommended illuminance levels for 50+ room types. Use these values with our lighting layout calculator to determine how many fixtures you need. For the full formulas behind the numbers, see our lighting calculation guide.

Commercial Industrial Residential Outdoor Healthcare Educational

Commercial Spaces

IES RP-1-20 recommended illuminance for office and commercial environments. Values represent maintained average illuminance on the work plane.

Space Type	Foot-candles (fc)	Lux (lx)	Task Type	IES Reference
Office - Open Plan	30-40	300-400	Computer work	RP-1-20
Office - Private	30-50	300-500	Reading, writing	RP-1-20
Conference Room	30-50	300-500	Meetings	RP-1-20
Lobby / Reception	10-20	100-200	Transient	RP-1-20
Corridor	5-10	50-100	Circulation	RP-1-20
Restroom	10-20	100-200	Grooming	RP-1-20
Stairway	5-10	50-100	Safety	RP-1-20
Retail - General	30-50	300-500	Merchandise	RP-2-20
Retail - Feature Display	100-200	1000-2000	Accent	RP-2-20
Restaurant - Dining	5-10	50-100	Dining	RP-6-20
Restaurant - Kitchen	50-100	500-1000	Food prep	RP-6-20
Hotel Lobby	10-15	100-150	Transient	RP-6-20
Bank Teller	50-75	500-750	Transaction	RP-1-20

Industrial & Warehouse

IES RP-7-22 recommended illuminance for industrial facilities. Use higher values for detailed or precision tasks. See our LED ROI calculator for retrofit savings.

Space Type	Foot-candles (fc)	Lux (lx)	Task Type	IES Reference
Warehouse - Bulk Storage	10	100	Bulk storage	RP-7-22
Warehouse - Active Storage	15-20	150-200	Active storage	RP-7-22
Warehouse - Order Picking	20-30	200-300	Picking, labeling	RP-7-22
Factory - Rough Assembly	10-20	100-200	Large parts	RP-7-22
Factory - Medium Assembly	20-50	200-500	Medium parts	RP-7-22
Factory - Fine Assembly	50-100	500-1000	Precision	RP-7-22
Factory - Inspection	50-200	500-2000	Quality control	RP-7-22
Machine Shop	30-50	300-500	Machining	RP-7-22
Loading Dock	10-20	100-200	Loading	RP-7-22
Welding Area	30-50	300-500	Welding	RP-7-22
Cold Storage	15-20	150-200	Storage, picking	RP-7-22

Residential

ANSI/IES RP-8-22 recommended illuminance for residential interiors. Values are average maintained illuminance at floor level unless noted.

Space Type	Foot-candles (fc)	Lux (lx)	Task Type	IES Reference
Living Room	5-10	50-100	General, social	RP-8-22
Living Room - Reading	20-30	200-300	Reading	RP-8-22
Kitchen - General	30-40	300-400	General	RP-8-22
Kitchen - Counter	50-75	500-750	Food prep	RP-8-22
Bathroom	20-50	200-500	Grooming	RP-8-22
Bedroom	5-10	50-100	General	RP-8-22
Bedroom - Reading	20-30	200-300	Reading	RP-8-22
Home Office	30-50	300-500	Computer work	RP-8-22
Dining Room	10-20	100-200	Dining	RP-8-22
Garage	10-20	100-200	Storage, parking	RP-8-22
Laundry Room	20-30	200-300	Laundry	RP-8-22
Hallway	5-10	50-100	Circulation	RP-8-22

Outdoor & Site Lighting

IES RP-43-22 and RP-8-22 recommended illuminance for exterior applications. Values are maintained average illuminance on the surface. Also see our solar street light calculator for off-grid sizing.

Space Type	Foot-candles (fc)	Lux (lx)	Task Type	IES Reference
Parking Lot - Low Activity	0.5-1	5-10	Basic security	RP-43-22
Parking Lot - High Activity	1-2	10-20	Shopping, event	RP-43-22
Walkway / Sidewalk	1-2	10-20	Pedestrian	RP-43-22
Street - Residential	0.5-1	5-10	Low speed road	RP-8-22
Street - Commercial	1-2	10-20	Medium traffic	RP-8-22
Building Entrance	5-10	50-100	Entry, security	RP-43-22
Gas Station Canopy	10-20	100-200	Service area	RP-2-20
Landscape - Accent	0.5-2	5-20	Decorative	RP-43-22
Loading Area	5-10	50-100	Truck loading	RP-7-22

Healthcare Facilities

IES RP-29-20 recommended illuminance for healthcare environments. Surgical and examination tasks require task-specific lighting in addition to ambient.

Space Type	Foot-candles (fc)	Lux (lx)	Task Type	IES Reference
Patient Room	10-20	100-200	General, rest	RP-29-20
Patient Room - Exam	50-75	500-750	Examination	RP-29-20
Examination Room	50-100	500-1000	Medical exam	RP-29-20
Surgery - General	200-500	2000-5000	Surgery (ambient)	RP-29-20
Surgery - Surgical Field	2500+	25000+	Surgical task light	RP-29-20
Laboratory	50-100	500-1000	Lab analysis	RP-29-20
Pharmacy	50-75	500-750	Dispensing	RP-29-20
Nurse Station	30-50	300-500	Charting, computer	RP-29-20
Waiting Room	10-20	100-200	Waiting	RP-29-20
Corridor	5-10	50-100	Circulation	RP-29-20

Educational Facilities

ANSI/IES RP-3-13 recommended illuminance for educational environments. Higher values apply for detailed tasks and older student populations.

Space Type	Foot-candles (fc)	Lux (lx)	Task Type	IES Reference
Classroom - General	30-50	300-500	Reading, writing	RP-3-13
Lecture Hall	30-50	300-500	Note-taking	RP-3-13
Library - Reading Area	30-50	300-500	Reading	RP-3-13
Library - Stacks	20-30	200-300	Browsing	RP-3-13
Science Laboratory	50-75	500-750	Experiments	RP-3-13
Art Classroom	50-100	500-1000	Art, color work	RP-3-13
Computer Lab	20-30	200-300	Computer work	RP-3-13
Gymnasium	20-30	200-300	Physical education	RP-3-13
Corridor	5-10	50-100	Circulation	RP-3-13

Frequently Asked Questions

What are IES recommended light levels?

IES recommended light levels are illuminance values published by the Illuminating Engineering Society (IES) in their Recommended Practice (RP) documents. They specify the minimum foot-candle or lux levels needed for different space types to ensure visual comfort, safety, and task performance.

How do I convert foot-candles to lux?

1 foot-candle (fc) equals 10.764 lux. To convert, multiply foot-candles by 10.764. For example, 30 fc = 323 lux. To convert lux to foot-candles, divide by 10.764.

What is the difference between maintained and initial illuminance?

Maintained illuminance is the average light level at the end of the maintenance cycle, accounting for lumen depreciation and dirt accumulation. Initial illuminance is the level when fixtures are new and clean. IES values are maintained values. Use a maintenance factor (typically 0.7-0.8) when sizing fixtures.

Which IES standard should I use?

The standard depends on the space type: RP-1-20 for offices, RP-7-22 for industrial, RP-8-22 for residential and roadway, RP-29-20 for healthcare, RP-3-13 for educational, and RP-43-22 for outdoor site lighting. Each document provides detailed design guidance beyond just illuminance values.