Lux to Lumens Calculator

Lux ↔ Lumens Calculator

Convert between illuminance and luminous flux

Lux Value (lx)

Area (m²)

Conversion Type Lux to Lumens Lumens to Lux

Conversion Result

0.00

Calculation details will appear here

Key Concepts

• Lux (lx): Measures illuminance (light received per unit area)

• Lumens (lm): Measures luminous flux (total light output)

Conversion Formula

$$\text{Lumens (lm)}=\text{Lux (lx)}\times \text{Area (m²)}$$

When to Use This

• Determining total light output needed for a space

• Matching light fixtures to room requirements

• Verifying lighting design specifications

Step-by-Step Calculation

1. Measure illuminance (in lux) at the surface

2. Calculate area being illuminated (in square meters)

3. Multiply lux by area to get lumens

Practical Example

For a desk that needs 500 lux illumination over 2 m²:

$$500\text{lx}\times 2{\text{m}}^2=1000\text{lm}$$

→ You'd need a 1000 lumen light source

Common Applications

Application	Recommended Lux	Area (m²)	Required Lumens
Office desk	500 lx	1 m²	500 lm
Kitchen counter	300 lx	4 m²	1200 lm
Living room	150 lx	20 m²	3000 lm
Retail display	1000 lx	3 m²	3000 lm

Important Considerations

1. Beam angle affects lux measurements (narrow beams = higher lux)

2. Reflective surfaces increase effective illuminance

3. Light loss factors (aging, dirt) may require 20-30% more lumens