Learn how to calculate how many lumens for a room and how to calculate square feet of a room. Get precise fixture quantities and spacing recommendations based on IES lighting standards.
Calculate square footage and target lumens for your room. Choose a fixture type to get suggested quantities.
Hotel guest rooms need 15 lm/sq.ft (161 lux) for a comfortable, restful guest atmosphere.
How to calculate square feet: Length × Width (in feet). If using inches, divide by 144. If using meters, area is in sq.m (㎡).
Room Area
0.00 sq.ft.
Target Lumens (20 lm/sq.ft)
0 lumens
Suggested Fixtures
0 pieces
Based on 800 lm per fixture
Calculate illumination requirements for commercial, office, and outdoor landscape projects.
Showrooms require high lux levels for product visibility and customer engagement.
Commercial LED panels typically output 800–2000 lm per unit.
Total Area
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Total Lumens (50 lm/sq.ft)
0 lumens
Suggested Fixtures
0 units
Based on 1200 lm per unit
Recommended Spacing
— ft apart
Enter dimensions to calculate
For high ceilings, downlighting or architectural pendant systems are recommended.
Multiply length × width to get square feet. For inches, divide by 144. Example: 12 ft × 10 ft = 120 sq.ft.
Multiply area by the recommended lumens per sq.ft. Living rooms: 20, kitchens: 40, bedrooms: 15. Based on IES standards.
Total lumens ÷ fixture lumens = number of fixtures needed. Example: 2,400 lm ÷ 800 lm pendant = 3 fixtures.
I was pricing out pendant lights for a restaurant project and had no idea how many fixtures I actually needed. Typed in 24×18 ft, selected showroom, got 27 fixtures at 1200lm each in like 5 seconds. The spacing suggestion was spot on — my electrician confirmed the grid layout made sense.
Always struggled with lumen calculations — kept over-lighting bedrooms and under-lighting kitchens. The IES standard numbers on here (20/40/15 lm per sq.ft) match what my lighting designer quoted me for $400. Wish I'd found this tool before paying for that consult.
Use this every time I quote a client now. The inches-to-sq.ft conversion alone saves me reaching for a calculator. Only thing I'd add is a save/PDF button, but for a free tool it does exactly what it says. The high-ceiling warning for commercial spaces is a nice touch.
Our lighting engineers can provide detailed photometric analysis and fixture recommendations for your project. Contact us through the main site and we'll respond within 12 hours.
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