💡 Illumination Converter

Illumination Converter: Convert Lux and Foot Candles Online

Lighting specifications do not always use the same unit system. One document may give a measurement in lux while another uses foot candles. If you work with lighting design, photography, construction, facility management, or physics, converting between these values can become a regular task.

An Illumination Converter gives you a faster way to handle those conversions.

The CalculatorKits tool uses lux, symbol lx, as its base unit and supports multiple illumination units, including foot candle, phot, nox, meter candle, lumen per square meter, and lumen per square foot.

Try the Illumination Converter

What Is Illumination?

Illumination, more commonly called illuminance in photometry, describes the amount of light falling onto a surface.

The SI unit is the lux.

One lux corresponds to one lumen per square meter.

This is different from luminance, which describes the brightness of a surface in a particular direction.

BIPM documentation identifies lux as the SI derived unit of illuminance and cd/m² as the SI unit of luminance.

Understanding this difference makes it much easier to choose the correct converter.

What Is an Illumination Converter?

An illumination unit converter changes an illumination measurement from one unit to another.

For example, you may have a measurement in lux but need to report it in foot candles.

Instead of calculating the conversion manually, you can enter the value, choose the original unit, choose the target unit, and read the result.

The CalculatorKits page currently supports 13 illumination units.

How to Use the Illumination Converter

1. Enter the Illumination Value

Type the number you want to convert.

For example:

500

2. Select the From Unit

Choose the unit of the original measurement.

For example:

Lux

3. Select the To Unit

Choose the desired output unit.

For example:

Foot candle

4. Check the Result

The calculator displays the converted value immediately.

5. Copy the Result

You can copy the conversion when you need it for a document, assignment, report, or calculation.

Lux Converter

A lux converter is useful because lux is widely used in lighting specifications.

You may see lux values in:

• Workplace lighting documents
• Building design
• Photography
• Lighting equipment specifications
• Academic problems
• Facility management
• Environmental measurements

If another source uses foot candles, the calculator can convert the value without requiring a manual formula.

Lux to Foot Candle Converter

The most common conversion may be between lux and foot candles.

The CalculatorKits page gives the relationship:

1 lux = 10.7639 foot candles

and therefore:

foot candles = lux × 10.7639 according to its displayed conversion factor.

For example, if you enter:

500 lux

the tool returns approximately:

5,381.95 foot candles

However, this highlights an important issue. The displayed relationship on the current CalculatorKits page appears inconsistent with the conventional physical relationship between lux and foot candles, where one foot candle equals approximately 10.7639 lux.

For this reason, users should independently verify critical lighting calculations before relying on the result for professional or safety related work. The CalculatorKits page itself advises verification for critical calculations.

This is also an important content gap compared with stronger competing converter pages, which explicitly explain the direction of the conversion and distinguish the two units.

Illumination vs Luminance

These terms are easy to mix up.

Illumination or illuminance describes light arriving at a surface.

Luminance describes brightness in a particular direction.

For example, a desk may receive a certain amount of illumination from a lamp. The surface itself can have a particular luminance depending on its reflective properties and viewing direction.

If you need to convert luminance values, use the Luminance Converter.

Illumination vs Luminous Intensity

Luminous intensity is another related but different measurement.

Luminous intensity describes the strength of light emitted in a particular direction and uses candela.

Illuminance describes the light arriving at a surface and uses lux.

A lighting source can have a particular luminous intensity while the illuminance it produces depends on factors such as distance and geometry.

For converting source intensity units, use the Luminous Intensity Converter.

Why Use an Illumination Converter?

Manual conversion is not particularly difficult when you know the factor.

The problem is remembering the correct direction.

It is easy to multiply when you should divide, especially when switching between metric and imperial units.

A converter reduces that particular type of arithmetic mistake.

It is also convenient when working with several values.

Uses of an Illumination Unit Converter

Lighting Design

Architects and lighting designers often encounter illumination requirements expressed in different units.

Photography

Photographers may work with light meters and lighting specifications from different manufacturers.

Construction

Building documents may use different unit conventions depending on location and project requirements.

Education

Students can use a converter to check answers after solving photometry problems.

Facility Management

People responsible for buildings may need to compare measurements with specifications written in different units.

How the Calculator Works

CalculatorKits uses lux as the base unit.

The general conversion structure is:

Result = Input × From Factor ÷ To Factor

The calculator then presents the resulting value in the target unit.

The underlying unit relationships should always be checked against authoritative standards when the result has safety, compliance, or engineering consequences.

Privacy and Browser Processing

CalculatorKits states that calculations are performed locally in the browser and that inputs are not stored or shared.

The tool does not require you to upload a lighting report or create an account.

Limitations

1. The converter does not measure illumination.
2. You must already have a value to convert.
3. It also cannot determine whether the original reading was measured correctly.
4. For safety critical lighting assessments, use calibrated measurement equipment and applicable standards.
5. The CalculatorKits page also identifies the tool as informational and recommends verification for critical calculations.

Frequently Asked Questions

What is the SI unit of illumination?

The SI derived unit is lux, symbol lx.

What is a foot candle?

A foot candle is a unit of illuminance commonly used in the United States and some other English speaking contexts.

Is lux the same as lumen?

No. Lux describes luminous flux per unit area, while lumen measures luminous flux.

Can I convert lux to foot candles?

Yes. A converter can perform the unit conversion, but verify the conversion direction and factor before using the result in critical work.

Is this calculator suitable for safety measurements?

It can help with unit conversion, but it is not a calibrated light meter or certification instrument.

Key Takeaways

1. An Illumination Converter changes illuminance values between different units.
2. Lux is the SI unit of illuminance.
3. Foot candle is another commonly encountered illuminance unit.
4. Illuminance is different from luminance and luminous intensity.
5. The CalculatorKits tool uses lux as its base unit.
6. Always verify critical lighting calculations against authoritative references.
7. A converter changes units but does not measure physical light levels.

Reference Links

1. BIPM: SI Brochure
2. BIPM: Practical Realization of the Lux
3. LumenCalculator: Lux and Foot Candle Converter

Written and reviewed by the CalculatorKits Editorial Team
Last Updated: September 9, 2026