Size a touch wayfinding screen from the tap: 0.2-inch capitals read at 30 to 60 cm, a 22-inch minimum for an interactive map, and a touch zone with nothing tappable above 48 inches off the floor. In a lobby that lands at 21.5 to 32 inches landscape on the wall or 32 to 43 inches portrait in a floor kiosk.
A lobby wayfinding screen is sized from two numbers: how far visitors stand when they tap, and how many lines the directory and map need at that distance. Visitors tap a wall or counter screen at 30 to 60 cm, about arm's length, so tapped text needs capitals around 0.2 inches tall, and the panel has to hold the whole map and directory without scrolling. In practice that lands a lobby sign at 21.5 to 32 inches landscape on the wall, or 32 to 43 inches portrait in a floor kiosk, with nothing tappable above 48 inches off the floor. This page works the math for a small college lobby, then lists the sizes worth quoting.
What sets the size
Three numbers decide it.
Tap distance sets the text height. Visitors tap standing at 30 to 60 cm. Text at that distance needs capitals of 0.2 inches: at 60 cm that is a height-to-distance ratio of about 1:120, and at 30 cm about 1:60, the generous end for interface text read at a glance while standing. Dim light or an older crowd moves the number up, not down.
Text height and line spacing set the line count. Plan line spacing at 1.7 times capital height, the same spacing rule used for distance signs. At 0.2-inch capitals, one directory line occupies 0.34 inches of panel height. Count the destinations and check the panel holds them beside the map.
Across-the-room pull sets the header. The same legibility rule that sizes a distance sign sizes the title: 1 inch of capital height reads from 30 ft (the FHWA planning figure), so a 1-inch header pulls from across a lobby and a 0.5-inch header from about 15 ft. The full distance-to-size table is in what size digital signage screen you need.
One floor: wayfinding kiosk guides put the minimum panel for an interactive map at 22 inches. Below that, the map and the list fight for pixels, so plan a looped directory with no tapping.
Sizes that work in a lobby
Information-kiosk guides put the workable range at 19 to 32 inches, with 22 inches the common interactive floor. Within that range:
| Setup | Panel size | What fits | Where it wins |
|---|---|---|---|
| Reception counter, landscape | 21 to 27 in | Directory and map tapped at 30 to 40 cm | Desks and service points short on floor space |
| Wall mount, landscape | 21.5 to 23.8 in at 1920 × 1080 | 30 to 34 lines at 0.34-inch pitch; a 14-item directory beside a map | Corridors and small lobbies; mounts flush |
| Wall mount, landscape | 32 in at 1920 × 1080 | About 46 lines at 0.2-inch capitals; headers legible deeper into the room | Larger lobbies; doubles as the notice board |
| Floor kiosk, portrait | 32 to 43 in | A tall map with the directory low on the face; kiosk bodies stand 1,600 to 2,100 mm | Mall-style signs that orient and advertise at once |
| Looped directory, small panel | 10.1 to 15.6 in | Rotating directory slides, no tapping | Side entrances and waiting rooms |
Touch type: order capacitive touch for a public lobby. Bare hands and fast taps suit it, and the glass front wipes clean. Resistive panels earn their keep with gloves and styli, which a lobby rarely sees; the trade-offs sit in the touch panel technology comparison.
Brightness: standard panels in this size class run 250 to 300 nits, which reads well on an interior wall. A lobby with full-height glazing needs a brighter panel, a hood, or a spot out of the sun path.
Step away from the table below 22 inches: drop interactivity and loop the directory. Above 43 inches portrait, the touch face no longer fits under the reach line on a wall, and the job moves to floor kiosks with a tilted screen.
Mounting height and the reach line
Keep every tappable control at or below 48 inches off the floor, the top of the accessible reach range under ADA guidance. That is what keeps the screen usable for a seated visitor as well as a standing one, and kiosk placement guidance adds knee and toe clearance for seated users. The title strip may sit above the line, because nobody taps the title.
For a wall panel, put the bottom of the touch area about 40 inches off the floor. A 21.5-inch landscape panel then spans 40 to 50.5 inches, with its top 2.5 inches reserved for the static title. Tall portrait panels cannot do this on a wall; the worked example below shows where a 43-inch portrait face lands.
Example: a two-story community college lobby
A small college wants mall-style wayfinding in the main lobby: a lookup list of places and a map visitors can tap, running without the campus network.
Inputs. Tap distance 30 to 60 cm, standing (planning figure for arm's-length taps). Directory of 14 destinations, one line each (the college's list). Capitals 0.2 inches tall (arm's-length planning figure). Line spacing 1.7 times capital height, so one line occupies 0.34 inches (distance-sign spacing rule). Panel under test: 21.5 inches, 16:9, 1920 × 1080, landscape (catalog panel data). Bottom edge of the face at 40 inches off the floor (the reach rule above).
Rule. Pixels per line = capital height ÷ pixel pitch. Lines available = panel pixel height ÷ pixels per line. Then check how much of the face sits below 48 inches.
Arithmetic. A 21.5-inch 16:9 face measures 18.7 by 10.5 inches. 1920 pixels across 18.7 inches gives a pixel pitch of 0.0098 inches. Capitals: 0.2 ÷ 0.0098 ≈ 20 pixels tall. Line pitch: 0.34 ÷ 0.0098 ≈ 35 pixels. Lines down the face: 1080 ÷ 35 ≈ 30 lines. The list column needs 14 destination lines plus a header and a prompt, about 20 of those 30. Mounting: the face spans 40 to 50.5 inches, so its top 2.5 inches stands above the 48-inch line and carries the static title only; every tappable control sits between 40 and 48 inches.
Result. The 14-item directory, header and prompt fit beside the map with no scrolling, and the whole touch zone sits between 40 and 48 inches off the floor, in reach for standing and seated visitors.
Decision. If the directory plus headers fit in about 30 lines at 0.34-inch pitch, the 21.5-inch 1080p landscape panel is enough; past 30 lines, or when the room reads from beyond about 15 ft, step to 32 inches. Portrait on a wall works only up to about 32 inches diagonal: its 27.9-inch-tall face fits under a 48-inch top edge with the bottom at 20 inches. A 43-inch portrait face is 21.1 inches wide and 37.5 inches tall; mounted with its top edge at 60 inches, the bottom edge sits at 22.5 inches and the top 12 inches of the face stands above the reach line, close to a third of the panel a seated visitor cannot tap. That is floor-kiosk territory, which is why this lobby gets the 21.5-inch landscape panel.
Lookup or loop: what runs without the network
A tap-to-route lookup is a software job. It needs kiosk software that searches a name and draws the route, running on hardware that runs that software, and it has to satisfy the campus IT policy; on a restricted network that means an offline license with no cloud account. Check that before the hardware is picked, not after.
The looped directory is the hardware job the offline signage units cover. The 21.5 and 23.8 inch units in our display range play images and video straight from a microSD card or a USB stick, with no subscription and no network connection. That is the right choice for the notice board by the door and the at-a-glance directory, and the wrong choice for the interactive map, because the included player loops slides; lookup software is not part of it. Lobby and reception displays and waiting room screens are placements where the loop board carries the traffic while the interactive kiosk does the routing. If the screen is for a seated operator watching live values, the sizing job is different: the offline kiosk display for an operator view covers that case.
What to ask for before you buy
- Panel size, orientation and native resolution on the quote, so the capitals can be checked against the pixel pitch before purchase.
- The touch option named on the quote: capacitive for a public lobby.
- Brightness matched to the wall's light, with any glazing called out.
- A mount that sets the bottom edge by the reach rule and keeps every control under the reach line, checked against the panel's outside dimensions.
- Content built at the panel's native resolution; if the sign is portrait, artwork prepared portrait-first, as in prepare portrait signage images for a mounted screen.
- For the lookup, kiosk software with an offline license that satisfies the IT policy, confirmed before the screen is ordered.
Recommendation: For a lobby or waiting-area sign that visitors tap at arm's length, choose a 21.5 to 23.8 inch landscape panel when the directory plus headers fit in about 30 lines, and a 32 inch panel when the list runs longer or the room reads from across the lobby. Keep the touch zone under the reach line with the title strip above it, order capacitive touch, run the lookup on offline-licensed kiosk software, and put a card-fed loop board beside the kiosk for at-a-glance notices.
Questions
Can one screen do the interactive map and the notice loop?
Two setups hold up better than one. The lookup needs kiosk software with a searchable map on hardware that runs that software; the loop board only plays slides from a card. Splitting them keeps the notice loop running while the interactive kiosk is updated, and each screen gets sized for its own job: the kiosk for tap distance and reach, the loop board for across-the-room reading.
Will a 15.6-inch touch panel work for wayfinding at a counter?
The text works: at 1920 × 1080 a 15.6-inch face has a pixel pitch of about 0.007 inches, so 0.2-inch capitals are about 28 pixels tall. The layout is the problem: about 22 lines of 0.34-inch pitch fit on the face, which holds a short list or the map, rarely both. Use a panel that small for a one-question lookup, one department per tap, or a looped directory with no tapping.
Does contrast matter as much as brightness in a bright lobby?
For taps, more. Dark text on a light map background stays legible at panel brightness where low-contrast artwork washes out. Check the real layout at the brightest hour of the day, standing where visitors stand, before approving the design; if the map greys out, add a hood, move the screen out of the sun path, or step the panel brightness up.
Planning information, not legal or engineering advice. Rules differ by place: check codes and permits with your local authority and your licensed trades.