Lux Calculator — Convert Lux to Foot-Candles and Find Target Levels
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320 lx equals 29.7 fc, 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 lux reading to foot-candles, or working out total lumens needed for a room at a target lux level.
One lux equals 0.0929 foot-candles, or one foot-candle equals 10.764 lux. Lux is one lumen of light falling on one square meter of surface — the metric counterpart to the foot-candle, and the unit most manufacturer spec sheets outside the US use.
Reference table
Target Lux Levels by Room
| Room | Target Lux | Target Foot-Candles |
|---|---|---|
| Hallway | 86 lx | 8 fc |
| Bedroom / Living Room | 161 lx | 15 fc |
| Kitchen (ambient) | 377 lx | 35 fc |
| Kitchen (task) | 915 lx | 85 fc |
| Bathroom | 431 lx | 40 fc |
| Office / Study | 431 lx | 40 fc |
| Garage | 269 lx | 25 fc |
| Storage | 161 lx | 15 fc |
Lux, lumens and layout
Lux vs. Lumens — and Why the Difference Matters for Layout
Area-dependent, not fixture-dependent
Lumens are a fixed property of a fixture — printed on the box, unaffected by the room. Lux is not: the same fixture delivers fewer lux the higher it is mounted or the larger the area its light spreads across, which is exactly why the lighting layout tool and every calculator on this site asks for ceiling height and room area rather than fixture output alone.
To go from a target lux level to a fixture count: multiply the target by the room's area in square meters for total lumens needed, then divide by a fixture's rated lumen output and round up.
Frequently asked questions
Lux FAQ
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What is lux?
Lux is one lumen of light falling on one square meter of surface — the metric unit of illuminance, used everywhere outside the United States and in most manufacturer spec sheets.
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How do I convert lux to foot-candles?
Divide lux by 10.764 to get foot-candles. The factor comes from the size difference between a square meter and a square foot — a square meter is 10.764 times larger, so the same light spread over it reads as a proportionally smaller lux-per-unit-area number when converted back.
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Is lux the same as lumens?
No. Lumens measure total light output from a fixture in every direction; lux measures how much of that light actually lands on a given surface area. A fixture rated at a fixed lumen output delivers fewer lux the farther it is from the surface, or the larger the area it is spread across.
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What lux level do I need for my room?
Residential rooms typically need 100–550 lux depending on use — around 90 lux for a hallway, 160 lux for a bedroom or living room, up to 375–1,075 lux for kitchen task areas. See the table above for the full range.
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How is lux measured?
With a lux meter (or a light-meter phone app calibrated in lux) held at the work surface being measured, pointed toward the light source — the same measurement method as foot-candles, just in the metric unit.
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Why do some fixtures list lux and others foot-candles?
It comes down to region and standard: American fixture packaging and IESNA design guidance use foot-candles, while European spec sheets, most lighting design software and metric building codes use lux. Both describe the same physical quantity.