Room Lighting Calculator

Calculation Method

The room lighting calculator determines proper lighting using these steps:

1. Room area = length × width (in square feet or square meters)
2. Foot-candles = recommended illumination level for the room type (IESNA guidelines)
3. Total lumens = room area (sq ft) × foot-candles required
4. Number of bulbs = total lumens ÷ lumens per bulb

Recommended Foot-Candles by Room

• Living room: 10–20 fc (ambient – task)
• Bedroom: 10–20 fc
• Kitchen: 30–40 fc (general), 70–80 fc (task areas)
• Bathroom: 30–40 fc (general), 70–80 fc (vanity)
• Home office: 40–50 fc (reading/writing), 60–80 fc (detailed work)
• Garage / workshop: 30–50 fc (general), 70–100 fc (workbench)

Bulb Efficiency Comparison

• LED: ~90 lumens per watt (most efficient, 15,000–25,000 hour lifespan)
• CFL: ~60 lumens per watt (moderate efficiency, 8,000–15,000 hours)
• Halogen: ~20 lumens per watt (3,000–5,000 hours)
• Incandescent: ~15 lumens per watt (least efficient, 750–2,000 hours)

Tips

• Use layered lighting: combine ambient, task, and accent lights
• Rooms with dark walls or furniture may need 10–20% more lumens
• Dimmer switches let you adjust brightness for different activities
• Color temperature matters: 2700K (warm) for bedrooms, 4000–5000K (cool) for offices

You can embed this util on your own site as a widget. Adding ?embed=1 to the URL loads a compact version with just the tool itself; no header, menu, or documentation. Paste this snippet into your HTML:

Copy snippet Adjust the height to taste.