Authoritative definitions of the International System of Units and SI prefixes.
Unit converters
Light & sound
Enter your values below for a clear, instant result.
Light & sound unitsInstant result
Decimals
Formula result = input × 1 ÷ 10.7639104167. 1 lx = 0.0929 fc
Common examples
One value, several units
Foot-candles0.0929 fc
Phot0.0001 ph
Nox1,000 nx
Conversion table
| lx | fc |
|---|---|
| 1 lx | 0.0929 fc |
| 2 lx | 0.1858 fc |
| 5 lx | 0.4645 fc |
| 10 lx | 0.929 fc |
| 25 lx | 2.3226 fc |
| 50 lx | 4.6452 fc |
| 100 lx | 9.2903 fc |
Conversion chart
1 lx0.0929 fc
5 lx0.4645 fc
10 lx0.929 fc
25 lx2.3226 fc
50 lx4.6452 fc
Worked example
1 foot-candle equals approximately 10.7639 lux.
Unit definition
Lux (lx) One lux equals 1 lux.
Unit history
Lux is represented here using its modern SI definition or an internationally accepted relationship to an SI base unit.
Step by step
1. Parse the value, including fractions.
2. Convert lx to lux.
3. Convert the base value to fc and apply your display precision.
Understand the result before using it
Light & sound converts illuminance, luminance, or sound pressure within the selected group. The numerical value changes because the size and definition of the selected unit changes; the underlying quantity does not.
Calculated result
The conversion follows the displayed unit relationship. Display rounding can hide additional digits, and measured inputs cannot become more accurate merely by changing units.
Formula, assumptions, and example
Formula
result = input × 1 ÷ 10.7639104167
Assumptions
- The source and target selections represent the same physical quantity or supported notation.
- The entered value is valid for the selected relationship and uses the source unit shown.
- Published unit definitions and conventional conversion factors apply under their stated conditions.
Worked example
1 foot-candle equals approximately 10.7639 lux.
When to use it
Good uses
- Translate a light & sound value found in a document, specification, recipe, or measurement.
- Compare values reported in different unit systems.
- Check a manual conversion and control the displayed precision.
Limitations
Common mistakes to avoid
- Decibel sound-pressure level is logarithmic and depends on the stated reference pressure.
- Do not add meaningful digits beyond the precision of the original measurement.
- Confirm regulated, safety-critical, laboratory, and contractual values against the controlling standard.
Sources and further reading
These references explain the underlying standards or provide authoritative context. Your own contract, institution, clinician, product documentation, local code, or governing standard may be the controlling source.
Guidance on unit names, symbols, conversions, and numerical presentation.
Questions about this calculation
What does the Light & sound converter do?
Light & sound converts illuminance, luminance, or sound pressure within the selected group. It does not change the physical quantity represented by the input.
What formula does the Light & sound converter use?
result = input × 1 ÷ 10.7639104167
Why can a Light & sound converter result be rounded?
UnitMora calculates with JavaScript double-precision numbers, then formats the result using your selected decimal or significant-figure setting. The unrounded value may contain more digits than are displayed.
What is the most common light & sound conversion mistake?
Decibel sound-pressure level is logarithmic and depends on the stated reference pressure.
Clear answers, without the guesswork
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