What is the difference between lux and lumens?

Lumens measure total light output from a source (luminous flux), while lux measures how much light reaches a surface (illuminance). The relationship is: Lux = Lumens / Area (m²). A 1000 lumen bulb produces 1000 lux at 1m², but only 250 lux when spread over 4m². Think of lumens as the total water from a hose, and lux as water per square meter on the ground.

How many lumens do I need for a room?

Multiply your target lux level by area (m²). For 500 lux in a 20m² office: 500 × 20 = 10,000 lumens needed. Standard lighting levels: 300-500 lux for offices, 500-1000 lux for retail, 750-1500 lux for detailed work, 50-100 lux for corridors. Our calculator includes these EN 12464-1 standards for quick reference.

What are the lighting standards for different spaces?

EN 12464-1 and IES standards specify minimum illuminance: Corridors 100 lux, Living rooms 150 lux, Offices 500 lux, Retail 500-1000 lux, Classrooms 500 lux, Workshops 750 lux, Precision work 1000-1500 lux, Surgery/labs 2000+ lux. Our calculator shows which standards your lighting meets.

How do I calculate lux from lumens?

Divide lumens by area in square meters: Lux = Lumens ÷ Area. For example, a 3000 lumen fixture over a 6m² desk: 3000 ÷ 6 = 500 lux. For non-square meter areas, convert first: 1 ft² = 0.0929 m². The calculator handles unit conversions automatically.

How many lights do I need for my space?

Calculate total lumens needed (lux × area), then divide by bulb output. For 500 lux in 25m²: 12,500 lumens needed. With 1200 lumen LED bulbs: 12,500 ÷ 1200 ≈ 11 bulbs. Add 20-30% for light losses to fixtures and surfaces. Our calculator provides estimates for common bulb types.

What is beam angle and how does it affect lux?

Beam angle determines how concentrated light is. A narrow beam (15°) produces high lux in a small area - good for accent lighting. A wide beam (120°) spreads light over a larger area with lower lux - good for general illumination. Same lumens through different beam angles give very different lux readings at the surface.

Lux to Lumen Converter

Convert between lux (illuminance) and lumens (luminous flux) based on area. Calculate lighting requirements for any space with standard recommendations.

EN 12464-1IES Handbook

Input Parameters

Enter illuminance or luminous flux value and area to convert