Illuminance Unit Converter
In lighting design, architectural daylighting assessment, photographic lighting setup, greenhouse management in agriculture, and workplace safety compliance, illuminance (light intensity) is a critical parameter. However, different regions around the world use different illuminance units:
- Lux (lx): The SI (International System of Units) standard, widely used in China, Europe, and most countries
- Foot-candle (ft-cd): Commonly used in the United States, especially in building codes, film/TV production, and HVAC design
Since these units are based on different length standards (meter vs. foot), their conversion factor is not an integer—making manual calculations prone to errors.
To solve this, we introduce a professional Illuminance Unit Converter that supports instant, bidirectional conversion between lux (lx) and foot-candles (ft-cd)—helping you cross the unit divide quickly and accurately!
🔁 Illuminance Conversion Formulas
Illuminance is defined as luminous flux per unit area (measured in lumens per square meter or square foot).
Given that 1 meter = 3.28084 feet, the area ratio is (3.28084)² ≈ 10.7639.
Core Conversion Relationships
| Direction | Formula |
|---|---|
| lx → ft-cd | ft-cd = lx ÷ 10.7639 |
| ft-cd → lx | lx = ft-cd × 10.7639 |
💡 Exact value:
1 ft-cd = 10.7639104167 lx
(For most engineering purposes, using 10.764 provides sufficient precision.)
💡 Common Illuminance Reference Table
| Lux (lx) | Foot-candles (ft-cd) |
|---|---|
| 1 | 0.0929 |
| 10 | 0.929 |
| 50 | 4.65 |
| 100 | 9.29 |
| 300 | 27.9 |
| 500 | 46.5 |
| 1,000 | 92.9 |
| 10,000 | 929 |
| 100,000 | 9,290 |
✅ Typical Scenario References
- Full moon at night: ≈ 0.1–0.3 lx (≈ 0.01–0.03 ft-cd)
- Living room (home): ≈ 100–300 lx (≈ 9–28 ft-cd)
- Standard office lighting: ≥ 500 lx (≈ 46.5 ft-cd)
- Operating room / precision assembly: ≥ 1,000 lx (≈ 93 ft-cd)
- Bright sunlight at noon: ≈ 100,000 lx (≈ 9,290 ft-cd)
✨ Tool Highlights
- Focused precision: Dedicated exclusively to the two core illuminance units—lx and ft-cd—for maximum simplicity
- High-accuracy computation: Uses the internationally recognized conversion factor (1 ft-cd = 10.7639104167 lx)
- Real-time conversion: Results appear instantly as you type—no “Convert” button needed
- Completely free · No ads · No registration required
- Cross-platform compatible: Works smoothly on smartphones, tablets, and desktop computers
🌐 Try It Now!
🔦 Make illuminance conversion simple, professional, and error-free!
Whether you're developing a lighting plan, interpreting international standards, calibrating studio lights, or completing coursework—this tool is your ideal assistant.
✨ Give it a try today—illuminate every detail with precise unit conversion!