Foot Candle Requirements by Space Type

A foot candle is one lumen landing on one square foot. Everything about whether a space feels right comes back to this number, how evenly it is spread, and where somebody measured it. Here are working targets for the spaces you are most likely to be quoting.

Warehouse and industrial

Space	Target	Measured at
Bulk storage, infrequent access	5 to 10 fc	Floor
Active storage, forklift traffic	10 to 20 fc	Floor
Rack aisles, order picking	20 to 30 fc	Vertical, in the aisle at rack face
General assembly	30 to 50 fc	30 inches above floor
Detailed assembly, machining	50 to 75 fc	At the work
Inspection, fine detail	75 to 100 fc	At the work, usually task lighting
Loading dock	20 to 30 fc	Floor, plus dock lights at doors
Mechanical and electrical rooms	20 to 30 fc	Floor

Fixtures: high bays above about fifteen feet, strip lights below that.

Office and commercial

Space	Target	Measured at
Open plan office	30 to 40 fc	Desk height, 30 inches
Private office	30 to 50 fc	Desk height
Conference room	30 to 40 fc	Table height, dimming worth having
Corridor, lobby	10 to 20 fc	Floor
Break room	20 to 30 fc	Table height
Restroom	10 to 20 fc	Floor, more at the mirror
Stairwell	10 fc minimum	Tread, and check egress requirements
Server or IT room	30 to 50 fc	Vertical at the rack face

Fixtures: panels and troffers in drop ceiling, down lights in hard ceiling, wraparounds in utility space.

Retail

Space	Target	Notes
General sales floor	30 to 50 fc	Higher for value retail, lower for premium
Feature and display	2 to 5x the general level	Contrast is what draws the eye, not raw level
Grocery, big box	50 to 75 fc	Uniform and bright is the whole aesthetic
Fitting room	30 to 50 fc	Colour rendering matters more than level
Checkout	50 fc	Vertical light on faces, not just down
Stockroom	20 to 30 fc	Floor

Schools and healthcare

Space	Target	Notes
Classroom	30 to 50 fc	Desk height, low glare, dimming for screens
Gymnasium	30 to 50 fc	Higher for competition play, uniformity critical
Library, reading	30 to 50 fc	Vertical light on the stacks too
Cafeteria	20 to 30 fc	Table height
Patient room	10 to 30 fc	General, with separate exam lighting
Exam room	50 to 100 fc	At the table, high colour rendering
Nurse station	50 fc	Work surface
Corridor, daytime	10 to 20 fc	Often reduced at night

Parking and exterior

Space	Target	Notes
Open parking lot, basic	0.5 to 1 fc average	Minimum matters more than average here
Open parking lot, enhanced security	1 to 3 fc average	Retail and hospitality typically
Parking garage interior	5 fc	Floor, and the fixtures run 24 hours
Garage ramps and entries	10 to 20 fc daytime	Eyes need a transition zone from daylight
Building entrance	5 to 10 fc	Vertical light on faces for cameras
Walkway, path	0.5 to 2 fc	Uniformity beats brightness
Loading and service yard	5 to 10 fc	Floor
Fuel canopy	20 to 30 fc	Under the canopy, and it is a dark sky issue

Fixtures: area lights on poles, wall packs on buildings, canopy under cover, bollards on paths.

The number nobody asks about: uniformity

Average foot candles will not tell you whether a space looks good. Uniformity will.

Space	Target ratio
Office, classroom, retail	3:1 or better
Warehouse general	4:1 or better
Parking lot	4:1, and no worse than 15:1 max to min
Sports and gym	2:1, which is why these layouts get dense

A parking lot at 1.5 foot candles average sounds fine until you find out it is 6 foot candles under each pole and 0.2 between them. The average is right and the lot is unusable, because the human eye adapts to the bright spot and then cannot see into the dark one. This is the single most common reason a client says the new lighting looks worse than what came out.

How to measure so the number means something

• Measure at the work plane, not the floor. Thirty inches for desks and benches. The floor is only the work plane in a warehouse.
• Take a grid, not a spot. Walk a pattern and record several readings. One reading directly under a fixture proves nothing.
• Kill the daylight. Measure at night or with blinds closed, or you are measuring the sun.
• Let LED settle. Give fixtures a few minutes to reach steady output before reading.
• Hold the meter flat and stand out of the way. Your own shadow will move a reading more than you expect.
• Record the existing levels before you demo anything. It settles arguments later, and it is what the utility asks for if a rebate is involved.

Turning a target into a fixture count

Once you have a target, the lumen method gets you to a fixture count in about two minutes. That method, with a worked example, is in how many high bays do you need for a warehouse. It works the same way for panels, strips and troffers, only the fixture lumens change.

One shortcut worth knowing: most of what we carry is wattage selectable, so you can lock the layout in first and set the output afterward once you have walked the space with a meter. That is a lot easier than reordering.