Calculate the optimal lighting requirements for any room based on size and purpose. Determine lumens, watts, and number of bulbs needed for proper illumination.
⚠️ Footcandle recommendations are ranges and vary by task type and personal preference. These are general guidelines, not precise requirements.
Last updated: March 2026 | By Patchworkr Team
Proper lighting is essential for comfort, productivity, and safety in any space. The amount of light needed varies significantly based on the room's purpose. Task-oriented spaces like kitchens and home offices require brighter lighting than ambient spaces like bedrooms or hallways.
Lighting levels are measured in foot-candles (fc), which represent the amount of light falling on a surface. One foot-candle equals one lumen per square foot. Lumens measure the total light output from a bulb, while watts measure energy consumption. Modern LED bulbs produce the same lumens as traditional bulbs while using 75-85% less energy.
This calculator uses industry-standard illuminance levels recommended by the Illuminating Engineering Society (IES) for residential spaces. These recommendations ensure adequate lighting while avoiding over-illumination, which wastes energy and can cause glare or eye strain.
Living room: 15 ft × 12 ft, requires 10-20 fc (use 15 fc average):
Multiple smaller lights distributed throughout the room provide better, more even illumination and reduce harsh shadows. A single bright light can create glare and uneven lighting. Aim for layered lighting with ambient, task, and accent sources.
Lumens measure light output (brightness), while watts measure energy consumption. With LEDs, you get more lumens per watt. A 60W incandescent produces 800 lumens, but an LED produces the same 800 lumens using only 8-10W.
Standard ceiling heights (8-9 ft) work well with flush or semi-flush mounts. For pendant lights, hang 30-36 inches above tables or counters. Recessed lights should be spaced at half the ceiling height (4-4.5 ft apart for 8-9 ft ceilings).
2700-3000K (warm white) for living rooms and bedrooms creates a cozy atmosphere. 3500-4100K (neutral white) for kitchens and bathrooms provides clear task lighting. 5000-6500K (daylight) for workshops and garages mimics natural daylight.
Yes! Over-illumination wastes energy, causes glare, washes out colors, and can cause eye strain and headaches. Use dimmers to adjust brightness for different activities. Stick to recommended foot-candle levels for each space type.
Color Rendering Index (CRI) measures how accurately colors appear under a light source. Look for bulbs with CRI 80+ for general use, 90+ for areas where color accuracy matters (kitchen prep, makeup application, art studios).
High ceilings (10-20 ft) need more lumens and wider beam angles. Use brighter bulbs or more fixtures, consider pendant lights to bring illumination closer to the living space, and use wall sconces or floor lamps to supplement overhead lighting.
Yes, but don't rely on it exclusively. This calculator assumes worst-case (nighttime) conditions. During the day, dimmers let you reduce artificial lighting. Place task lights away from windows to minimize glare, and use window treatments to control natural light.