Free tool · Conference room display size
What Size Display Does Your Conference Room Need?
This calculator sizes the display for a conference room from the farthest seat and what people look at, using the 4/6/8 viewing ratios that AVIXA's DISCAS standard grew out of. It returns the minimum image height, the display size to buy, when two displays are the better answer, and the camera field of view needed to frame the table.
01 Calculator
Enter the room and the farthest seat
Two measurements from a tape or the floor plan, plus what people will look at. The seat and table fields fill themselves from the room when you leave them blank.
02 Your result
The display this room needs
Enter the room length and width above and press Size the display to see the minimum image height, the display size to buy and the camera field of view.
- Display size to buy
- The smallest common commercial size at or above the minimum diagonal.
- Minimum image height
- Farthest seat divided by the viewing ratio for what people look at.
- Minimum diagonal, 16:9
- Image height x 2.04. Displays are sold by this measurement.
- Farthest seat that size serves
- At the same viewing ratio; seats beyond it see text too small.
- Displays
- Two when the image would pass 98 inches or the room is wider than it is long.
- Camera field of view needed
- Horizontal angle to frame the table or front row from the nearest seat.
- Camera to look for
- Wide-angle above 90 degrees, standard otherwise.
A 16:9 display is about . Check the wall width, the mounting height and the furniture under it before you order.
Why two displays.
Camera.
Microphones. The display math says nothing about audio, and audio is what people complain about. Every seat needs a microphone within comfortable reach: a video bar's own array covers a huddle room, a boardroom table usually needs table or ceiling microphones along its length, and classroom rows need ceiling coverage over the rows. A room that echoes needs acoustic treatment before it needs more microphones.
03 How it is calculated
How is the display size calculated?
The farthest seat divided by a viewing ratio gives the image height; everything after that is 16:9 geometry.
- Farthest seat as entered, or room length - 3 ft of clearance at the back wall
- Maximum viewing ratio 6 for video calls and slides (basic decision making), 4 for spreadsheets and drawings (analytical)
- Minimum image height farthest seat / viewing ratio
- Minimum diagonal, 16:9 image height x 2.04
- Display size to buy the smallest of 55, 65, 75, 85, 98 in at or above the minimum diagonal
- Camera field of view 2 x atan((table or front-row width / 2) / distance to the nearest seat)
Assumptions
- The viewing ratio is the farthest viewer distance divided by the image height, the quantity AVIXA's DISCAS calculator solves for. We cap it at 6 for video calls and slides (basic decision making) and 4 for spreadsheets, drawings and fine detail (analytical decision making), the 4/6/8 rule as Epson states it. Passive viewing of video alone allows 8; conference rooms rarely show video alone, so it is not offered.
- DISCAS (ANSI/AVIXA V202.01:2016) replaced the rule of thumb with a method based on the height of the smallest element on screen and two acuity factors, 200 for basic and 3438 for analytical decision making. It needs your font size and resolution, so this calculator stays with the ratio method and names your category; an integrator runs the DISCAS numbers for the final design.
- The image is the content area, not the display. When a call shows people and content side by side on one display, the content image is smaller than the display, which is the strongest case for a second display.
- Clearance when a seat or table field is blank: 3 ft (0.91 m), the minimum clear width of walking surfaces in the ADA Standards (section 403.5.1). Measure your own room and overwrite it.
- The common commercial sizes are 55, 65, 75, 85, 98 inches; above 98 inches the options are two displays, a projector or a direct-view LED wall. Sizes are nominal diagonals; check the exact dimensions on the model's specification sheet.
- The camera angle is the horizontal field of view needed to see the full width of the table or front row from the nearest seat: 2 x atan((width / 2) / distance). Above 90 degrees we recommend a camera or video bar listed at 110 degrees or more; Yealink's MeetingBar A30, for example, lists a 120 degree field of view. People sitting beyond the table edge need a little more than the table width.
- Not covered: mounting height and ceiling height (DISCAS adds a vertical check), lighting and glare, and how the room is used for anything other than the content you chose.
Sources
- AVIXA, "Display Image Size for 2D Content in Audiovisual Systems" (ANSI/AVIXA V202.01:2016), standard page
The DISCAS standard, document number 202.01:2016, published May 2016: it "establishes display size and viewing positions for new or existing spaces from drawings or on-site" and "determines required display image size and relative viewing positions based on user need". The document is sold; the calculator is free.
- AVIXA, DISCAS calculator: analytical and basic decision making calculations
"The Viewing Ratio is calculated as the Farthest Viewer/Image Height." The analytical calculator works from image height, vertical image resolution, farthest viewer and viewing ratio; this tool divides the farthest seat by the same ratio.
- AVIXA, "Learn more about display image size" (DISCAS terms)
The image is "the active image area displaying a user's content", an element is "a group of pixels conveying an item of information (e.g., a character at a given font size)", and the acuity factors are 200 for basic decision making and 3438 for analytical decision making.
- Epson, "How to Select the Right Display Size" (April 6, 2018)
The 4/6/8 rule as applied here: four times the display height for analytical viewing (spreadsheets, charts and web content), six for basic viewing (presentations and multimedia), eight for passive viewing (video conferencing, videos). "If the attendee is farther than eight times the display height, they will not be able to clearly see text and images on the display surface."
- rAVe [PUBS], "When Size Matters: Projection Screens" (March 12, 2013)
The rule as a formula, screen height = distance of the farthest viewer / detail factor, with factors 4 (engineering drawings, medical images, very fine detail), 6 (web pages, spreadsheets, simple presentations) and 8 (motion video), and the worked example of a 24-foot room needing a 4-foot image height. It files spreadsheets under 6; this tool uses the stricter 4 from Epson.
- Draper, Inc., "Is the Display Big Enough?" (June 3, 2016)
Calls it "the long-established 4/6/8 Rule used by the audio visual industry for determining display sizes": four times the height for analytical viewing, six for basic viewing, eight for passive viewing, and shows classrooms where a 65-inch display left most seats beyond the basic viewing distance.
- Draper, Inc., "New InfoComm Display Size Standard" (January 15, 2016)
Why the standard superseded the old best practices, which "were based on technologies that are no longer in use today in most places" and "just didn't scale well" as resolution increased, and the variables it introduced: element height, acuity factor, image offset and vertical viewing factor.
- U.S. Access Board, ADA Accessibility Standards, section 403.5.1 Clear Width
"The clear width of walking surfaces shall be 36 inches (915 mm) minimum." The clearance this tool assumes between the seats, the table and the walls when you leave the seat and width fields blank.
- Yealink, MeetingBar A30 product page
One example of a wide-angle video bar: "a 4K camera with 120° field of view", "designed for medium rooms".
04 Sizes compared
How far does each display size reach?
Image dimensions from 16:9 geometry, and the farthest seat each size serves at the two viewing ratios, in the units you chose.
| Display, 16:9 | Image height | Image width | Farthest seat for calls and slides (6 x height) | Farthest seat for spreadsheets and drawings (4 x height) |
|---|---|---|---|---|
| 55 in | 27 in | 47.9 in | 13 ft 6 in | 9 ft |
| 65 in | 31.9 in | 56.7 in | 15 ft 11 in | 10 ft 7 in |
| 75 in | 36.8 in | 65.4 in | 18 ft 5 in | 12 ft 3 in |
| 85 in | 41.7 in | 74.1 in | 20 ft 10 in | 13 ft 11 in |
| 98 in | 48 in | 85.4 in | 24 ft | 16 ft |
Read it both ways: a 75-inch display serves a room whose farthest seat is within the distance in its row, and a room with a farther seat needs the next size up. The farthest-seat columns are the image height times 6 and times 4, the same arithmetic the calculator runs on your room.
05 What to do about it
What to do with the figure
- Design
Conference room AV, designed and installed
Displays, cameras, microphones and one-touch join for huddle rooms, boardrooms and training rooms, installed by our Irvine team and supported afterwards.
- Compare
Microsoft Teams Rooms vs Zoom Rooms
Which room system fits your office, how each handles guests on the other platform, and what the hardware choice means for the room you just sized.
- Check
Conference room AV checklist for an Orange County office
The questions to settle before the quote: room use, display, camera, microphones, cabling, lighting and who supports it.
- Quote
Get a quote for this room
Send us the dimensions and this result; we come back with a design for the display, camera and microphones and a price for installing it.
06 Questions
Questions about conference room display size
What is the 4/6/8 rule for display size?
An audio visual rule of thumb: the farthest viewer should sit no more than four display heights away for analytical content such as spreadsheets and drawings, six for basic content such as slides and video calls, and eight for passive video. Divide the farthest seat distance by that ratio and you have the minimum image height this tool reports.
How is the DISCAS standard different from the 4/6/8 rule?
DISCAS, ANSI/AVIXA V202.01:2016, sizes the image from the smallest element people must read, a character at a given font size, using two acuity factors: 200 for basic decision making and 3438 for analytical decision making. It replaced the rule of thumb because older practice did not scale with resolution. This tool keeps the ratios and names your category.
Does a 4K display let people sit farther from it?
No. Higher resolution makes each pixel smaller, which lets the nearest viewer sit closer without seeing them; it does not make a given font larger for the farthest seat. Basic decision making depends on element height, while analytical decision making depends on the image resolution, which the AVIXA calculator ties to the farthest viewer. Size for the back row first.
When should a conference room have two displays?
When the minimum image works out larger than a 98-inch display, when the room is wider than it is long, or when video calls matter: with one display, people and shared content split the screen, so the content image is smaller than the display. A second display gives content a whole screen and the side seats a straighter view.
What camera field of view does a boardroom need?
Enough to see the people at the near end of the table: twice the arctangent of half the table width over the distance to the nearest seat. A long, narrow table needs a modest angle; a wide table close to the display pushes past 90 degrees, where a wide-angle video bar, 110 degrees or more, is the answer.
Next step
Get a Quote for This Room.
Send us the room dimensions and this result. Our Irvine team designs the display, camera and microphone layout, installs it and supports it afterwards, for Microsoft Teams Rooms, Zoom Rooms or a plain presentation room. Or start with the conference room AV page and the Teams Rooms versus Zoom Rooms comparison.
Last reviewed: . Published by Telxpress, Irvine, CA.