Convert lux to lumens instantly with our professional lighting calculator.Includes area calculations, foot-candles conversion, and UK lighting standards for electricians, lighting designers and facilities managers.
Essential formulas for lighting designers, electricians and facilities managers in the UK
The fundamental conversion formula. Multiply illuminance (lux) by the area in square metres to get total luminous flux (lumens) required.
Complete formula including Utilisation Factor (UF) and Maintenance Factor (MF) for accurate professional lighting calculations.
Calculate illuminance when you know total luminous flux. Essential for checking compliance with BS standards.
Convert between metric (lux) and imperial (foot-candles) units.1 foot-candle = 10.764 lux exactly.
Estimate LED power consumption. Modern LEDs typically produce 100-150 lumens per watt depending on efficiency.
Emergency lighting calculation for escape routes.BS 5266-1 requires minimum 1 lux on escape routes.
Required lux levels for different applications according to British Standards and HSE guidelines
| Application / Area | Required Lux | British Standard | Notes |
|---|---|---|---|
| Office Work (Computer) | 300 lux | BS EN 12464-1 | Screen-based work, minimum requirement |
| Office Work (Paper) | 500 lux | BS EN 12464-1 | Reading, writing, detailed tasks |
| Emergency Escape Routes | 1 lux | BS 5266-1 | Minimum on escape route centreline |
| Emergency Open Areas | 0.2 lux | BS 5266-1 | Areas >60m² with escape routes |
| Emergency High-Risk Areas | 15 lux | BS 5266-1 | Potential hazards, level changes |
| Corridors & Circulation | 100-200 lux | BS EN 12464-1 | Movement areas, lobbies |
| Meeting Rooms | 300-500 lux | BS EN 12464-1 | Conference rooms, presentation areas |
| Retail General | 300-750 lux | BS EN 12464-1 | General merchandise areas |
| Industrial Assembly | 300-750 lux | BS EN 12464-1 | Depends on task complexity |
| Warehouse Storage | 100-300 lux | BS EN 12464-1 | General storage and handling |
| Car Parks | 20-75 lux | BS EN 12464-1 | Traffic routes and parking areas |
| Stairways | 150 lux | BS EN 12464-1 | Safety requirement for steps |
Practical examples of lux to lumens conversions for common UK scenarios
Requirement: 20m² office needs 300 lux for computer work (BS EN 12464-1)
Result: Need approximately 12,500 total lumens from light fittings
Requirement: 30m corridor (2m wide) needs 1 lux minimum for escape route
Result: 60 lumens minimum from emergency lighting (typically 3-4 emergency lights)
Requirement: 50m² retail space needs 500 lux for merchandise display
Result: Need approximately 44,600 total lumens from lighting system
Requirement: 200m² warehouse area needs 200 lux for general storage
Result: Need approximately 114,300 total lumens from high-bay lighting
Requirement: 15m² consulting room needs 500 lux for examination tasks
Result: Need approximately 15,600 total lumens for adequate examination lighting
Requirement: 80m² restaurant needs 200 lux for comfortable dining
Result: Need approximately 33,300 total lumens for ambient dining lighting
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Common questions about lighting calculations, conversions and UK standards
Use the formula: Lumens = Lux × Area (m²).For professional installations, multiply by Utilisation Factor (UF) and Maintenance Factor (MF): Lumens = Lux × Area × UF × MF. Our calculator includes these factors automatically.
Lumens measure total light output from a bulb or fixture (like water from a hose).Lux measures how much light actually reaches a surface (like water pressure).1 lux = 1 lumen per square metre.
BS EN 12464-1 requires 300-500 lux for UK offices.This equals 300-500 lumens per square metre at desk level. For total fixture lumens, divide by utilisation factor (typically 0.6) and maintenance factor (typically 0.8).
Yes. BS 5266-1 requires minimum 1 lux on escape routes. Enter 1 lux and your corridor area to calculate minimum lumens needed from emergency lights. Remember this is the minimum - actual installations often exceed this.
1) Find required lux level (BS EN 12464-1).2) Measure room area (L×W).3) Calculate basic lumens (Lux × Area).4) Apply efficiency factors for total fixture lumens.Our calculator handles all steps automatically.
1 foot-candle = 10.764 lux exactly.To convert: Lux = Foot-candles × 10.764, or Foot-candles = Lux ÷ 10.764.Our calculator shows both metric (lux) and imperial (foot-candles) values.
Utilisation Factor: 0.4-0.7 depending on room reflectance and fixture type.Maintenance Factor: 0.7-0.9 depending on cleaning schedule and environment.Use 0.6 UF and 0.8 MF for typical office calculations.
Modern LEDs produce 100-150 lumens per watt.Our calculator uses 120 lm/W for estimation. Actual efficiency varies by manufacturer, colour temperature and driver quality.Always check manufacturer specifications.
The lux to lumens calculation is the same - light measurement is independent of source type.However, LED efficiency (lumens per watt) is much higher than fluorescent, so you'll need fewer watts for the same light output.
Yes.Calculate existing lumens from current lux readings, then compare with required levels per BS standards.The calculator shows exactly how many lumens you need to add or can remove during LED upgrades.
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