Lighting Calculator

Determine the optimal lighting requirements for any room based on its size and purpose. Our free calculator helps you achieve the perfect balance of brightness, whether you're planning a cozy living room or a well-lit workspace.

Calculate Lighting Needs for Your Room

What are your brightness needs?

Brightness needs will depend on the activity or work being performed in the space, as well as personal preference. Input your brightness needs, in footcandles:

Room Area:

Results

 

 

How to Calculate Room Lighting

Step 1: Identify Room Type

Different rooms require different lighting levels:

  • Living Room: 20 lumens per sq ft (215 lumens per sq m)
  • Kitchen: 30 lumens per sq ft (323 lumens per sq m)
  • Bedroom: 15 lumens per sq ft (161 lumens per sq m)
  • Bathroom: 20 lumens per sq ft (215 lumens per sq m)
  • Office: 30 lumens per sq ft (323 lumens per sq m)

Step 2: Measure Room Area

Calculate the total square footage (or square meters) of your room by multiplying the length by the width. For irregularly shaped rooms, break them down into rectangular sections and add the areas together.

Step 3: Calculate Total Lumens Needed

Multiply the room's square footage (or square meters) by the recommended lumens per square foot (or square meter) for that room type. This gives you the total lumens needed for proper illumination.

Step 4: Choose Light Fixtures

Common light bulb lumens:

  • Standard LED bulb: 800 lumens
  • Bright LED bulb: 1600 lumens
  • Recessed light: 500-1000 lumens
  • Pendant light: 400-800 lumens

Frequently Asked Questions

What's the difference between lumens and watts?

Lumens measure brightness; watts measure energy usage. Modern LED bulbs use fewer watts to produce the same lumens as older incandescent bulbs.

How do I distribute lighting in a room?

Use a combination of ambient, task, and accent lighting. Ambient lighting provides overall illumination, task lighting focuses on specific areas, and accent lighting highlights features.

What's the best color temperature for different rooms?

Use warmer temperatures (2700K-3000K) for living spaces and bedrooms, and cooler temperatures (3500K-5000K) for kitchens, bathrooms, and workspaces.

How many lumens do I need for a kitchen or bathroom?

Kitchens and bathrooms typically need brighter lighting than living rooms or bedrooms. As a rule of thumb, aim for about 70–80 lumens per square foot (753-861 lumens per square meter) in task-intensive areas. For example, a 100 sq ft (9.3 sq m) kitchen (or bathroom) might require on the order of 7,000–8,000 lumens for adequate brightness. This is significantly higher than the ~1,000–2,000 lumens recommended for a 100 sq ft (9.3 sq m) bedroom or living room.