Illuminance Converter
Free online illuminance converter. Convert illuminance units easily. Converts the illuminance conversion in one unit to the other unit. This online illuminance unit converter allows quick and accurate conversion between many units of measure, from one system to another. The illuminance conversion page provides a solution for engineers, translators, and for anyone whose activities require working with quantities measured in different units.
Illuminance Conversion Online
Illuminance is a measure of the amount of light falling on a surface, expressed in units of luminous flux per unit area. An illuminance converter is a tool used to convert illuminance from one unit of measurement to another.
Common units of illuminance include:

Lux (lx): a metric unit of illuminance, equal to one lumen per square meter.

Footcandle (fc): a nonSI unit of illuminance, equal to one lumen per square foot.

Phot: a unit of illuminance, equal to one lumen per square centimeter.
Illuminance converters can be found online and are used to convert illuminance from one unit to another. To use an illuminance converter, the user inputs the illuminance value in the original unit and selects the desired output unit. The converter then calculates and provides the converted value.
Illuminance is an important factor in many lighting applications and is used to determine the amount of light required for a given task or area. An illuminance converter helps to make it easier to convert illuminance values from one unit to another, which can be useful in a variety of applications, including lighting design, energy efficiency assessments, and photometric testing.
How do you calculate illuminance?
Illuminance is calculated by dividing the total luminous flux incident on a surface by the area of the surface. The formula for illuminance is:
E = Φ / A
Where:
E = Illuminance (in lux or foot candles)
Φ = Luminous flux (in lumens)
A = Area of the surface (in square meters or square feet)
To calculate illuminance, the luminous flux of a light source must first be determined. This can be done by measuring the total light output of the source in lumens. The illuminance at a surface can then be calculated by dividing the total luminous flux by the surface area. The resulting value is the illuminance in units of lux or foot candles.
It is important to note that illuminance is a measure of the amount of light incident on a surface and is dependent on the surface area and the distance of the light source from the surface. To accurately calculate illuminance, both the luminous flux of the light source and the surface area must be accurately measured.
What is the unit of illuminance?
The unit of illuminance is lux (lx). Lux is a metric unit of illuminance, equal to one lumen per square meter. Another unit used to measure illuminance is the foot candle (fc), which is a nonSI unit of illuminance and is equal to one lumen per square foot. The phot is another unit of illuminance and is equal to one lumen per square centimeter. The choice of a unit depends on the specific application and the preference of the user.
What is illuminance value?
Illuminance value is the amount of light falling on a surface, expressed in units of luminous flux per unit area. It is a measure of the amount of light incident on a surface and is usually expressed in lux (lx) or foot candles (fc).
The illuminance value is an important factor in many lighting applications and is used to determine the amount of light required for a given task or area. It is used in lighting design, energy efficiency assessments, and photometric testing, among other applications. The illuminance value is calculated by dividing the total luminous flux incident on a surface by the area of the surface. The resulting value is the illuminance in units of lux or foot candles.
How do you convert illuminance to luminance?
The conversion from illuminance (E) to luminance (L) requires knowledge of the surface reflectance (ρ) and the angle of incidence (θ). The formula for converting illuminance to luminance is:
L = ρ * E * cos(θ)
Where:
L = Luminance (in cd/m^2 or ftL)
ρ = Surface reflectance (dimensionless ratio)
E = Illuminance (in lux or fc)
θ = Angle of incidence (in radians)
The surface reflectance (ρ) is a measure of how much light is reflected by a surface. It is a dimensionless ratio and can range from 0 (no reflection) to 1 (complete reflection). The angle of incidence (θ) is the angle between the light source and the surface. It affects the amount of light that is reflected by the surface and can range from 0 (perpendicular) to 90 (grazing).
To convert illuminance to luminance, the surface reflectance (ρ) and angle of incidence (θ) must be known. The illuminance is then multiplied by the surface reflectance and the cosine of the angle of incidence to obtain the luminance in units of cd/m^2 or ftL.