Illuminance Converter

Why Use This Illuminance Converter?

Accurate light measurement is non-negotiable for professionals. Whether you are balancing exposure for photography, ensuring OSHA compliance in a workspace, or calculating optimal light for horticulture, precision matters. This Illuminance Converter eliminates the need for manual math, instantly switching between metric units (Lux) and imperial units (Foot-candle).

Unlike generic calculators, this tool handles scientific units like Phot and Millilux with 10-decimal precision, ensuring your lighting blueprints and exposure settings are flawless.

How to Use

1. Input Value: Enter your current light reading in the top field.
2. Select Units: Choose your source unit (e.g., Lux) and target unit (e.g., Foot-candle).
3. Get Results: The tool converts instantly. Click "Copy Result" to paste the data directly into your reports.

Frequently Asked Questions

How do you convert EV to lux?

Use the formula Lux = 2.5 × 2^EV. This calculation assumes a standard light meter calibration constant (C) of 250 and ISO 100. Consequently, an Exposure Value (EV) of 15 equates to approximately 82,000 lux.

How do you calculate illuminance?

Illuminance is calculated by dividing Luminous Flux by the surface area. The formula is E (Lux) = Φ (Lumens) / A (m²). For example, 1,000 lumens distributed evenly over 2 square meters results in an illuminance of 500 Lux.

What is the difference between luminance and illuminance?

Illuminance measures the light falling onto a surface (incident light), typically in Lux or Foot-candles. Luminance measures the light reflected off a surface toward the eye (brightness), measured in candela per square meter (cd/m²).

How to convert lumen into lux?

You cannot convert directly without area dimensions. Lux is Lumens per square meter. To convert, divide your total Lumens by the area (in m²) being lit. Without the area variable, the conversion is mathematically impossible.

How many lux is full sun?

Direct sunlight typically ranges from 100,000 to 120,000 lux. In contrast, an overcast day drops to approximately 1,000 lux, while standard office lighting is usually around 500 lux.