If you’re building, renovating, or just ready for a change in lighting, there’s nothing worse than spending hours researching and choosing a light fixture, only to get it home and find out that a measurement got missed somewhere along the way and it won’t work the way you wanted.

Before you buy, read and bookmark this article for quick reference. When you’re armed with the best information, you’ll make the best choices. 

And remember, the very best way to get your information right from the get-go is to ask a lighting expert – so don’t skip the trip to your local lighting showroom! They’ll be able to help you avoid any common mistakes and help you get what you want right from the start.

Understanding Light Output

You’ll want to get familiar with a couple of vocab words before jumping in. 

• Watts: The amount of energy or electricity a bulb uses. Has nothing to do with brightness.
• Foot Candles: The amount of perceivable light from a fixture at one foot away.
• Lumens: The amount of overall light given off by a light source. Has nothing to do with power consumption.

How These Terms Relate To Each Other

Comparing a fixture or bulb’s wattage and lumens will show its efficiency. A bulb with low wattage and high lumens uses less power to generate more light, meaning it will cost less to light your home. 

Not all rooms are created equal – bedrooms generally need less light than a kitchen. To determine how many lumens you need, multiply the square footage of the space by the foot candle recommendation. For example, a typical 300 sqft bedroom will need around 3000-6000 lumens in total. [Sqft of room x min and max foot candles = Total min and max lumens needed]

This total includes all types of light in the room, from ceiling fixtures to lamps to sunlight. For best results, you never want to have all of the light in a room come from a single source. A great lighting plan considers the times of day the room will be used, accent lighting like reading lamps, and activities that happen in the room. If your room can transition perfectly from busy daytime work to a relaxed evening at home, then you’ve nailed it.   

Universal Standard Measurements

While most fixtures have their own set of standard measurements for placement and sizing, there are a handful of things that are universal. For brevity’s sake, we’ve put those things here rather than repeating them for each fixture. 

• Height and Head Clearance: Keep at least 7’ of clearance between the bottom of the fixture and the floor. If there is any chance that a hanging fixture could be in the way, especially in places like hallways and stairs, raise the fixture a bit more to avoid accidents. Vaulted or high ceilings may need more clearance between the fixture and the floor to look balanced. Lower fixtures will make a room feel more intimate, while higher fixtures are less noticeable (which is sometimes the goal).
• Door Clearance: If you’re installing a fixture near a door, keep 6” of clearance between the bottom of the fixture and the top of the door.
• Weight Limit: Modern standard ceiling light boxes are manufactured to hold up to 50 pounds when installed correctly. It’s important to check the weight of your fixture and the structure of your ceiling before installing any ceiling fan or a fixture over 35 pounds. Installing the extra support doesn’t usually cost much – and it’s way cheaper than paying for damages if an improperly supported fixture falls.
• Dining Table: The max width of a light fixture over a dining table should be around 1/2-3/4 the width of the table. The bottom of the fixture should be just above your seated eye level so that it doesn’t obstruct the view – usually about 30-36” from the table surface. Always center the fixture over the table, not in the center of the room. [table width x ½ and ¾ = min and max fixture width]
• Great Rooms and Multi-Purpose Rooms: You’ll want to consider all angles when choosing fixtures for rooms with multiple uses. For example, many great rooms have a dining room between the kitchen and living room. You’ll still want to follow standard dining fixture recommendations to start – but you’ll also need to hang your fixture high enough to avoid glare and an obstructed view while standing and using the rest of the space.

Standard Measurements by Fixture

Standard measurements will work well in almost every home, but there’s always room to bend the rules a little for a fixture you love or in a unique space. For rooms or areas not mentioned, refer to the general standards and/or rooms with similar uses.

FLUSH AND SEMI-FLUSH LIGHTS

• General Sizing: Add the length and width of the room in feet together, then record that number in inches to determine the best width for a ceiling fixture. For example, a 10’x20’ living room can accommodate a 30” wide ceiling fixture. (This formula works well for most ceiling-mounted lights, not including fixtures like ceiling fans and recessed lights.) [room length in feet + room width in feet = optimal ambient fixture width in inches (no conversion, just change the units)]
• General Placement: Flush and semi-flush lights are generally installed in the center of a room, or over the center of a specific-use area like a dining table. Flush mounts work best in rooms with standard ceiling heights at 8’, and may feel dim if installed on a tall ceiling. Semi-flush lights hang down from the ceiling, and work great in rooms with 9-10’ ceilings. 
• Bathroom: It’s best to maintain 8’ between the top of the bathtub and the bottom of a fixture. Flush mounts are a great choice for ambient lighting in a bathroom, but they don’t work well as the only light in a bathroom, as they can create shadows on the face. For best use in the bathroom, combine your ceiling fixture with a pendant or sconce near the mirror.

PENDANTS 

• General Sizing: For single pendants, the same room length in feet + room width in feet = fixture width in inches formula from above works well. For grouped pendants, sizing depends largely on personal preference and the available space for installation. 
• General Spacing: When hanging multiple pendants, the minimum spacing between them should be about 18”. For larger pendants, the recommended minimum spacing is equal to the diameter of the pendants. For example, 20” wide pendants should be hung at a minimum of 20” apart.
• Kitchen Island: There are many ways to hang pendants over an island, and there isn’t one hard-and-fast set of rules. Here are a few guidelines to consider:
  • For islands up to 6’ wide, the max is usually two pendants, but you can sometimes get away with three small pendants if you prefer that look. For islands over 6’ wide, many homeowners choose to use three or more pendants to maximize light coverage across the countertop.
  • To determine how far away from the edge of the island pendants should be, divide the diameter of the pendant in half. For example, the side of 18” pendants should be a minimum of  9” away from the edge of the island. [pendant width / 2 = recommended distance from pendant to edge of island]
  • A large, single pendant should not exceed 2/3 of the island’s width. For example, the widest you’d want to go on a pendant over a 6’ island is about 48”. [total island width x ⅔ = max pendant width]
• Sinks and Counters: The standard distance from the counter for a pendant is 30-40” but 36” and above is best. When using pendants for task lighting, choose a fixture that allows the light to shine in the right place – a pendant with a solid bottom won’t light a counter very well.
• Bedroom: As a reading light above a bedside table, aim for the lighted portion of the pendant to be about 55-60” above the floor or 30-36” above the mattress. 

CHANDELIERS

• General Sizing: To determine the ideal diameter, add the length and width of your room together in inches. For example, a 15×20 room would need a chandelier approximately 35” in diameter (15+20=35). To determine the ideal height of the fixture, plan on around 2-3” of height for each foot of ceiling height. For example, in a home with 8’ ceilings, a chandelier should be about 16-24” tall (8×2=16, 8×3=24). A two-story foyer in that home can easily support a chandelier that’s 32-48” tall (16×2=32, 16×3=48). [room length in feet + room width in feet = optimal chandelier width in inches (no conversion, just change the units)], [ceiling height in feet x 2 and 3 = min and max chandelier height]
• General Placement: Chandeliers are a bold design choice intended to stand out and make a statement. They’re almost always placed in the center of a room, or centered over a part of a room with a specific use, like a dining table or a clawfoot bathtub.
• Dining Table: In a room with 8’ ceilings, the standard height is about 30-36” above the table, then add 3” for every foot over 8’ in ceiling height. Always center the chandelier over the table, not in the center of the room.
• Two-story foyer: Keep the bottom of the chandelier above the height of the first floor.

SCONCES

• General Sizing: When it comes to sizing and scale, there isn’t a great universal formula here – it’s left largely up to personal preference and a good eye. A good rule of thumb for sconces is this: The closer you’ll be standing to look at whatever the sconce is lighting, the smaller the sconce should be. 
• General Placement: Sconces are usually placed around eye level, around 60-72” from the floor. In rooms with higher ceilings, 66-72” will feel more balanced. Take into consideration the style of the fixture – a sconce with a bare bulb will feel more comfortable a bit above eye level, whereas a sconce with a shade will feel more comfortable if the shade is at eye level to avoid catching the glare of the bulb from under or above the shade.
• Dining Room: Because people will be seated for the majority of the time, sconces should be hung slightly lower in the dining room – closer to 60” from the floor.
• Bathroom: Sconces work best placed on either side of the mirror at eye level, around 4-12” away from the edges depending on the look you’re after and where the electrical boxes can be installed. Sconces can also be centered above the mirror at just above eye level, usually between 60-70” off the floor. 
• Bedroom: As a reading light above a bedside table, aim for about 55-60” above the floor or 30-36” above the mattress. 
• Porch, Patio, Doors: When choosing a sconce to go near an exterior door, look for one that is 1/4 – 1/3 of the height of the door. For example, the most common standard door height is 80”. To determine the best sconce size, 80” ÷ 4 = 20” and 80” ÷ 3 = 26.6’ tell us to look for a sconce that is around 20-26” tall. Generally speaking, outdoor sconces should be positioned at around 66-72” above the ground at the center of the light. You can fudge the high end a little for extra tall spaces, but going above 72” isn’t usually recommended. [height of exterior door x ¼ and ⅓ = min and max of sconce]
• Garage: The best practice is to put a sconce on either side of every garage door, with the bottom of the fixture around 1’ from the top of the garage door. With this configuration, opt for fixtures that are 1/4 – 1/3 of the height of the door. For example, an 8’ garage door will look best with sconces that are 24”-32” (96” ÷ 4 = 24” and 96” ÷ 3 = 32”). When hanging lights centered over the garage doors instead, be sure that the fixtures are large enough to light the full width of the driveway. [height of garage door x ¼ and ⅓ = min and max of sconce]

RECESSED LIGHTS

• General Sizing: Standard recessed lighting is typically 4-6” wide. 6” lights are the most common and are most often used for general lighting. 4” and 5” lights are often used for task or accent lighting, such as providing extra light over a kitchen counter. 
• General Placement for Ambient Lighting: The number of lights you’ll need will vary greatly depending on the size and brightness of the lights, the size of the room, and the height of the ceiling. The formulas below will get you a good rough estimate, but it’s usually a good idea to stop in at a lighting showroom and check in with an expert when planning a recessed light layout. There are a lot of things to consider, and recessed lighting is difficult to move after the fact if you run into an issue. 
  • Amount – A good place to start is to multiply the room’s square footage by the recommended foot candles to calculate the total lumens you’ll need. Then, divide the total lumens by the lumen output of the recessed lights you want to use. For example, for a 300 sqft bedroom, requiring 10-20 foot candles, using 370-lumen lights, you’ll want to stick to around 8-16 lights (300 x 10 ÷ 370 = 8.1) and (300 x 20 ÷ 370 = 16.2). [room sqft x min and max foot candles = total lumens min and max], [total lumens min and max / one light’s lumen output = min and max number of lights needed]
  • Spacing – It’s always best to follow the manufacturer’s recommendation, but a good rule of thumb for planning is to divide the ceiling height in half to determine how far apart the lights should be. Divide that number in half again to determine how far away from the wall the lights should be. For example, in a room with 8’ ceilings, space your lights about 4’ apart and 2’ from the wall. [ceiling height / 2 = distance between lights, distance between lights / 2 = distance from wall]
  • Zoning – If you have a room that serves multiple purposes (like a great room or a living room with a home office nook), measure and map out each area separately when planning your overall layout.
  • Existing fixtures – It’s very common for a room to have a grid of recessed lights in addition to a statement fixture like a chandelier or a ceiling fan. You’ll want to plan around the fixture location and take its light into account.
  • Furniture – A bright recessed light directly above a couch can feel uncomfortable and create shadows. In these situations, try to place lights around the perimeter and in the middle of the room to help with glare.
  • Dimmer switch – Sometimes a grid of overhead recessed lights can feel a little harsh. We always recommend installing a dimmer switch for your lights so that you can always feel comfortable in your space.
• General Placement for Task or Accent Lighting: Recessed lights are also used for supplemental lighting in places where that need a bit more light, like over a kitchen counter, a piano, a reading nook, etc. Place these accent lights based on where you need the light, but choose carefully – you want your task lighting to shine on your task rather than on your head or in your eyes. Some recessed lights can be angled, which makes getting the light in just the right spot a bit easier.

CEILING FANS

• General Sizing: Ceiling fan sizes are measured by the diameter of the blades, or the blade span. The size fan you need is determined by the size of the space it needs to cool. An undersized fan will feel weak and underwhelming, but a fan that’s too large can turn a room into a wind tunnel. Size recommendations can vary a little depending on the manufacturer, but this chart will give you a general idea of what size fan you’ll need:

• General Placement: For 8’ ceilings and lower, you’ll need a flush mount or hugger fan that attaches directly to the ceiling to keep the required 7’ minimum clearance to the floor. You also need at least 8” of clearance between the blades and the ceiling for optimal airflow. For ceilings over 8’, look for a ceiling fan with a downrod, which will drop the fan away from the ceiling. Aim to have your ceiling fan around 8-9’ above the floor for the best airflow.
• Airflow Efficiency and CFM: Cubic Feet per Minute refers to the amount of air moved per cubic foot that a ceiling fan can move in one minute at its highest setting. The higher the CFM, the more air a fan moves. To determine the efficiency of a fan, divide a fan’s CFM by the Watts. An efficiency score of 75 is the minimum requirement to label a fan as energy efficient. [CFM / Watts = Airflow Efficiency]

TABLE LAMPS

• General Sizing: Measure the height of the furniture the lamp will be on. Aim for a lamp that’s around ⅔ the height of the furniture, and avoid going above 1.5 times the height. (You may want to go smaller for lamps placed on taller furniture to avoid glare.) The widest part of the lamp and shade should be smaller than the width of the furniture. [best standard lamp height = table height x ⅔]
• General Placement: Best practice with table lamps states that the lamp should be at about eye level when you’re near it. For lamps near couches and chairs, that’s typically around 58-64”. Whether you spend most of your time sitting or standing in a room, the bottom of the shade should be around eye level to avoid accidental glare above or below the shade.

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Don’t get stuck in the muck – if you’re planning a lighting project, save the stress and stop by our showroom. All we do is lighting – and we do it right. You’ll get free expert advice and access to thousands of fixtures – and customer service that you just can’t beat at a big-box store or shopping online. Skip the headache, and stop on by. We’ll see you soon!