Foot Candle Calculator — Convert FC to Lux and Find Your Target

Choose a mode

Lux323 lx
Conversion Factor× 10.764

30 fc equals 323 lx, since 1 foot-candle equals 10.764 lux by definition — one lumen spread over a square foot versus a square meter.

Switch between converting a single foot-candle reading to lux, or working out total lumens needed for a room at a target foot-candle level.

One foot-candle equals 10.764 lux. A foot-candle is one lumen of light landing on one square foot of surface — American fixture packaging and IESNA design standards use foot-candles, while European spec sheets and metric building codes use lux.

Reference table

Target Foot-Candle Levels by Room

Recommended foot-candle and lux targets by room type (IESNA ranges).
Room Target Foot-Candles Target Lux
Hallway 8 fc 86 lx
Bedroom / Living Room 15 fc 161 lx
Kitchen (ambient) 35 fc 377 lx
Kitchen (task) 85 fc 915 lx
Bathroom 40 fc 431 lx
Office / Study 40 fc 431 lx
Garage 25 fc 269 lx
Storage 15 fc 161 lx

Measurement and lighting design

How Foot-Candles Are Measured — and Why They Matter for Recessed Lighting

Work-plane, not floor level

A light meter measures foot-candles at the surface that matters — desk height for an office, counter height for a kitchen — not the floor. This is the same distinction the lighting layout tool and every room-specific calculator on this site build in: the target level is always a work-plane measurement.

For recessed lighting specifically, foot-candles are the bridge between a target brightness and a fixture count: multiply the target by the room's floor area for total lumens needed, then divide by a fixture's rated output and round up.

Frequently asked questions

Foot-Candle FAQ

  • What is a foot-candle?

    A foot-candle is one lumen of light falling on one square foot of surface. It is the common unit of illuminance in the United States — the amount of light actually landing on a surface, not the total output of a bulb.

  • How do I convert foot-candles to lux?

    Multiply foot-candles by 10.764 to get lux. One foot-candle equals 10.764 lux because a square meter is 10.764 times larger than a square foot, so the same light counted over the metric area gives a proportionally larger number.

  • What foot-candle level do I need for my room?

    It depends on the room: 5–10 fc for a hallway, 10–20 fc for a bedroom or living room, 30–50 fc for a kitchen or office, and 70–100 fc for kitchen task areas. See the table above for the full range.

  • Is foot-candle the same as lumens?

    No. Lumens measure the total light output of a fixture in every direction; foot-candles measure how much of that light actually reaches a surface. The same fixture delivers fewer foot-candles the farther it is mounted from the floor.

  • How are foot-candles measured?

    With a light meter (or light-meter phone app) held at the surface being measured — usually the work plane, such as desk or counter height, rather than the floor — pointed straight up toward the ceiling fixtures.

  • How do foot-candles relate to recessed lighting layout?

    The target foot-candle level for a room, multiplied by its floor area, gives the total lumens needed — divide that by a fixture's rated lumen output and round up for a fixture count. This is the core of the lumen method used throughout this site's calculators.