Foot-Candles to Lux Calculator
Convert foot-candles (fc) to lux (lx): lx = fc × 10.76391. Free online tool — no sign-up. Clear formulas and worked examples. Runs locally in your browser.
Trust summary Engine tested · Specification checked · v1.1.0
- Input interpretation
- Enter values to calculate.
- Result
- —
- Model
- Illuminance unit conversion between foot-candles and lux.
- Scope
- Same illuminance; only the unit system changes
- Verification
- Engine tested · Specification checked · v1.1.0
- Named expert review
- Optional · Not performed
- Specification basis
- 1 fc = 1 lm/ft²; 1 lx = 1 lm/m²; 1 m² = 10.76391 ft²
Formulas
Core equations used by this calculator.
How to use
Choose direction
fc → lx for SI lux, or lx → fc for foot-candles.
Enter the illuminance value
Use a light-meter reading or a design target in fc or lx.
Read the converted unit
Same brightness, different area basis (ft² vs m²).
Example calculations
Common configurations with formula and result.
1 fc
Definition
10 fc
Common round number
50 fc
Retail / classroom target
100 fc
Default
lx → fc
500 lx
Foot-candles ↔ lux
Common values at a glance.
| fc | lx (×10.76391) | Notes |
|---|---|---|
| 1 | 10.76 | 1 lm/ft² |
| 5 | 53.82 | — |
| 10 | 107.64 | Warehouse general (min) |
| 30 | 322.92 | Office / classroom (min) |
| 50 | 538.20 | Retail / pick-pack typical |
| 75 | 807.29 | Higher classroom / retail |
| 100 | 1076.39 | Competition sports / bright task |
| 1000 | 10763.91 | Very high industrial / studio |
Foot-Candles to Lux calculator specification
Version 1.1.0 · Engine tested
- Engine tested 4 published cases
- Named expert review Not performed
- Calculation version 1.1.0
- Definition
- A foot-candle (fc) is one lumen per square foot (lm/ft²). A lux (lx) is one lumen per square meter (lm/m²). Because 1 m² = 10.76391 ft², 1 fc = 10.76391 lx. So lx = fc × 10.76391 and fc = lx ÷ 10.76391 (≈ lx × 0.092903).
- What it calculates
- Illuminance unit conversion between foot-candles and lux.
- Inputs
- Foot-candles (fc) or lux (lx)
- Outputs
- Lux (fc → lx) or foot-candles (lx → fc)
- Formula
lx=fc×10.76391; fc=lx÷10.76391- Assumptions
- Same illuminance; only the unit system changes
- Units
- fc ↔ lx
- Boundary conditions
- 0 maps to 0
- Example
- 100 fc → 1076.391 lx
- Validation cases
4 published on this page
- 1 fc → 10.76391 lx
- 50 fc → 538.1955 lx
- 100 fc → 1076.391 lx
- 500 lx → fc → ≈ 46.4515 fc
- Specification basis
- 1 fc = 1 lm/ft²; 1 lx = 1 lm/m²; 1 m² = 10.76391 ft²
- Calculation version
- 1.1.0
Background
Interpretation and common distinctions.
Convert foot-candles (fc) ↔ lux (lx).
E((lx)) = E((fc)) × 10.76391 E((fc)) = (E((lx)))/10.76391
Default: 100 fc → 1076.391 lx.
What fc and lux measure
| Unit | Definition | Region |
|---|---|---|
| Foot-candle (fc) | 1 lm / ft² | Common in North America |
| Lux (lx) | 1 lm / m² | SI / international |
Both describe illuminance — how much light lands on a surface — not total lamp output (lumens) or directional intensity (candela).
Typical levels (guide)
| Application | Approx. fc | Approx. lx |
|---|---|---|
| Parking (open) | 1–5 | 11–54 |
| Warehouse (general) | 10–30 | 108–323 |
| Office | 30–50 | 323–538 |
| Retail / classroom | 30–75 | 323–807 |
| Manufacturing / hospital | 30–100 | 323–1076 |
| Sports (competition) | 50–100+ | 538–1076+ |
Use project codes and lighting standards for final targets; fixture count also depends on CU, LLF, and layout — not conversion alone.
Related tools
Other calculators in this family: Lumen to Lux, Candela to Lux, Lux to Candela, Watts to Lux .
Frequently asked questions
Key distinctions behind the calculation.
How do I convert foot-candles to lux?
Multiply by 10.76391: lx = fc × 10.76391. Quick round: ×10.764. Example: 50 fc ≈ 538.2 lx.
How do I convert lux to foot-candles?
Divide by 10.76391: fc = lx ÷ 10.76391 (or multiply by ≈0.092903). Example: 500 lx ≈ 46.45 fc.
What is a foot-candle?
One foot-candle is one lumen of luminous flux uniformly distributed over one square foot — the customary U.S. unit of illuminance. Equivalent to 1 lm/ft².
What is a lux?
One lux is one lumen per square meter (lm/m²) — the SI unit of illuminance used worldwide.
Is 1 fc exactly 10.76 lx?
More precisely 10.76391 lx (from 1 m² = 10.76391 ft²). Guides often print 10.76 or 10.764.
Are foot-candles the same as lumens per square foot?
Yes — 1 fc = 1 lm/ft². Likewise 1 lx = 1 lm/m².
What foot-candle levels are typical indoors?
Rough guides: parking ~1–5 fc, warehouse general ~10–30 fc, offices ~30–50 fc, retail ~30–75 fc, competition sports often 50–100+ fc. Always check project standards.
Do I need area or distance for this conversion?
No — fc ↔ lx is a pure unit change for the same illuminance. Use lumen-to-lux when converting total flux over an area.