How Many Lumens Do I Need for a Room? – Insights

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How a lot gentle is sufficient to gentle a room? Most designers and designers use two foundational rules of lighting design when planning and specifying lighting for any house:

  • the qualitative (or aesthetic) side of sunshine 
  • the quantitative (or engineering) side of sunshine

Calculating for whole lighting required is taken into account quantitative.

The lumen methodology is essentially the most generally used for calculating the full gentle output wanted on your house. With this components, you first set up the meant use of the house, then you definately measure its sq. footage.

This information will assist you to perceive what the lumen methodology is and easy methods to calculate it. You may as well use the lumens calculator beneath to find out what number of lumens you want based mostly on room measurement and different key variables.

Desk of contents:

  1. Helpful Lighting Terms
  2. The Lumen Method – How to Calculate Lumens
  3. Footcandle Requirements for Various Applications
  4. Summary: Calculating Total Lumens Needed for a Room
  5. Factoring in Lumen Lighting Variables
  6. Lumens Calculator
  7. Accounting for Personal Taste

Useful Lighting Phrases


Lumen output is a measurement of the full amount of seen gentle emitted by a light-weight supply. It’s additionally generally often called brightness or gentle output.

The reference level: A typical 100-watt incandescent gentle bulb produces about 1,500-1,700 lumens. Strictly talking, 600 LED lumens supplies the identical quantity of sunshine as 600 incandescent lumens.

LED lights present larger Colour Rendering Index (CRI), so, whereas they extra precisely reveal the colours of the topic being lighted, they don’t present extra gentle.


Wattage is a measure of how a lot electrical energy (or vitality) a light-weight bulb consumes to realize its lumen output.

Every sort of sunshine supply — LED, fluorescent, halogen or incandescent bulbs — has a distinct lumen-to-watt ratio. If a 100-watt incandescent gentle produces 1,500 lumens, and a 10-watt LED gentle does the identical, the 10-watt LED bulb might declare 100-watt equivalency and vitality effectivity.

Right here’s a lumen-to-watt chart. Please notice that these ratios might differ barely, even between totally different  LED merchandise.


Foot-candle is the unique measurement system for gentle depth on a one square-foot floor from a uniform supply of sunshine. In different phrases, a foot-candle is the sunshine measured one foot away from a candle.

Contemplating the human-centric rules of lighting design, the IES (the biggest society {of professional} lighting designers) supplies a footcandle chart on what number of foot-candles of sunshine people have to carry out duties comfortably in numerous areas.

For instance, for laundry dishes, they advocate that your lighting supplies 20 foot-candles of sunshine at two ft, six inches off the ground. That is additionally known as the horizontal goal.

The Lumen Technique – Tips on how to Calculate Complete Lumens Wanted

  1. Decide room measurement by sq. footage. Multiply the size occasions the width of the room to get the room sq. footage. For instance, if the room is 10 ft broad and 10 ft lengthy, the room sq. footage will likely be 100 sq. ft.
  2. Set up the footcandle requirement on your utility. Lighting necessities differ relying on the kind of room being lit, often known as the appliance. For instance, a toilet or kitchen would require extra foot candles than a lounge or bed room. As soon as you identify the meant use of your house, browse this footcandle chart for the IES-recommended footcandle requirement on your utility.
  3. Multiply the room sq. footage by the footcandle requirement. For instance, a 100 square-foot lounge, which wants 20 foot-candles, will want 2,000 lumens. A 100 square-foot eating room, which wants 40 foot-candles, would require 4,000 lumens.
Graphic that compares total lumen output in a living room to a dining room with 3 lamps (220 lumens each) and a ceiling fan with a ceiling light in a dining room
Graphic showing the preferred LED lighting layout. LED lights placed towards the center of the room are more efficient than lights placed in the corners

We’ve created a useful information to How Many Lumens You Want that walks you thru this calculation in additional element.

Business Lighting Footcandle Necessities

Room Foot-candles Wanted
Places of work: Common Studying and Writing 50-75
Places of work: Hallways 10-20
Places of work: Rooms with Computer systems 20-50
Auditoriums / Meeting 15-30
Hospitals: Normal Areas 10-15
Hospitals: Labs / Therapy Rooms 75-100
Libraries 50-100
Faculties 30-100

Residential Lighting Footcandle Necessities

Room Foot-candles Wanted
Dwelling Room 10-20
Kitchen: Normal 30-40
Kitchen: Range 70-80
Kitchen: Sink 70-80
Eating Room 30-40
Bed room 10-20
Hallway 5-10
Rest room 70-80

Abstract: Calculating Complete Lumens Wanted for a Room

Let’s recap easy methods to gauge how a lot gentle you want for an area. Multiply your room sq. footage by the footcandle requirement. For instance, a 100-square foot lounge, which wants 20 foot candles, will want 2,000 lumens. A 100-square foot eating room, which wants 40 foot-candles, will want 4,000 lumens.

Obtain a Free Footcandle Chart »

Factoring in Lumen Lighting Variables

Ceiling Peak Variable

Notice: Solely learn this part in case your ceiling peak is taller than 10ft. In case your ceiling peak is beneath 10ft, the Lumen Technique above and the lumens calculator beneath will likely be adequate for figuring out the required gentle output on your utility.

When you’ve got excessive ceilings in an area, then you should account for that in your lumens calculation. You try this with a footcandle multiplier.

To calculate on your advisable footcandle multiplier, use the next formulation:

footcandles (fc) = cd ÷ h

cd = candlepower

h = distance between the lamp and the horizontal goal

As soon as you establish your required footcandle degree, you multiply that by your room’s sq. footage.

Wall Colour Variable

When you’ve got particularly dark-colored partitions and furnishings or for those who’re utilizing lighting fixtures with shades, you’ll want roughly a further 10 lumens per sq. foot.

Lumens to Candlepower Conversion

Candlepower is a unit of measurement for luminous depth. It expresses ranges of sunshine depth relative to the sunshine emitted by a candle of particular measurement and constituents.

The historic candlepower is the same as 1.02 candelas. In fashionable utilization, candlepower is typically used as a synonym for candela.

Lumen output = C/0.07958

Lumens Calculator

Use this calculator to calculate the lumens wanted to gentle a room.

Please notice that these are estimations. For precise evaluation, please seek the advice of a lighting design skilled.

Accounting for Private Style

Private desire will play a big function in figuring out how a lot gentle you want in an area. Should you just like the room to be particularly vivid, chances are you’ll need to add a further 10-20% to our numbers after which set up dimmers to regulate the sunshine to desired ranges.

When lighting is correctly designed in an area, you discover the room and the objects in it. In different phrases, you discover what the lighting illuminates, not the lighting merchandise themselves. Unhealthy or poor lighting design exhibits up as sizzling spots, darkish spots and unintentional shadows.

Good or environment friendly lighting design accounts for whole normal and activity lighting required for an area. Dynamic or superior lighting design components the qualitative, human expertise. It lights for vertical (not merely horizontal) visible impressions, corresponding to partitions — in addition to ceilings with uplighting to reduce shadows and darkish spots for easy, streamlined and evenly distributed gentle.


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David Hakimi

David Hakimi

Alcon Lighting artistic director and co-founder David Hakimi works to enhance lighting by analysis, growth and schooling. David strives for effectivity in lighting, affording architects, lighting designers and engineers the flexibility to maximise LED lighting design and utility.
David is a graduate of the College of California, Los Angeles, the place he acquired a Bachelors in historical past. David additionally studied lighting design at IES in Los Angeles. He traces his and Alcon Lighting’s dedication to innovation, accountability, high quality and worth to classes realized from his father, Mike Hakimi, a lighting craftsman, salesman and marketing consultant in Southern California for greater than 4 many years.
Right this moment’s lighting for industrial use requires a deep, full understanding of good lighting techniques and controls. David takes pleasure in his lighting, vitality controls and design data. He’s pushed by the will to share his insights into lighting specification and utility. This quest to share his data was the impetus for David to create Insights, Alcon Lighting’s weblog and useful resource heart for serving to the reader perceive lighting and its utility to house.

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