Visual characters and letter height
Non-glare, contrasting, conventional letterforms, at least 40 in above the floor, with a minimum height from Table 703.5.5: 5/8 in for a sign 40 to 70 inches up and read from under 6 feet, rising by 1/8 in per foot of extra distance, and 2 in or 3 in for higher signs (703.5).
Table 703.5.5: minimum character height
| Baseline height above floor | Horizontal viewing distance | Minimum height (uppercase I) |
|---|---|---|
| 40 in to 70 in | under 72 in (6 ft) | 5/8 in |
| 72 in and more | 5/8 in + 1/8 in per ft over 6 ft | |
| over 70 in to 120 in | under 180 in (15 ft) | 2 in |
| 180 in and more | 2 in + 1/8 in per ft over 15 ft | |
| over 120 in | under 21 ft | 3 in |
| 21 ft and more | 3 in + 1/8 in per ft over 21 ft |
Viewing distance is the horizontal distance to the nearest obstruction that stops someone getting closer: a counter, a railing, a row of seats. Height is measured to the baseline. The character height calculator does the arithmetic and rounds up to the next 1/16 inch.
Two worked examples. A department sign above a reception desk, baseline at 84 inches, with the desk keeping visitors 10 feet away: the 70 to 120 inch row, under 15 feet, so 2 inches minimum. A wayfinding sign hung at 9 feet over an atrium balcony, read from 30 feet across the void: over 70 to 120 inches (108 inches), 30 feet is 15 feet past the 15 foot threshold, so 2 inches plus 15 × 1/8, or 3 7/8 inches.
The other visual requirements
| Requirement | Value | Section |
|---|---|---|
| Finish | non-glare, characters and background | 703.5.1 |
| Contrast | light on dark or dark on light | 703.5.1 |
| Case | upper, lower or mixed | 703.5.2 |
| Style | conventional; no italic, oblique, script or decorative | 703.5.3 |
| Proportion: width of O vs height of I | 55%–110% | 703.5.4 |
| Height above floor | 40 in min to baseline | 703.5.6 |
| Stroke thickness of I | 10%–30% of height | 703.5.7 |
| Character spacing | 10%–35% of height | 703.5.8 |
| Line spacing, baseline to baseline | 135%–170% of height | 703.5.9 |
Where raised characters with braille do double duty as the visual characters, they only have to meet the finish and contrast rule of 703.5; the rest of 703.5 does not apply to them (703.5 exception). Elevator car control characters are exempt from the 40 inch minimum.
Condensed fonts fail the proportion test more often than anything else on visual signs: narrow faces pulled in to fit a long room name push the O below 55 percent of the I. Set the text at the minimum height first, then size the sign around it, rather than squeezing text into a sign size the client picked.
Exterior signs and long distances
The ADA's visual rules apply to the signs it covers: room designations, directional and informational signs about the facility, and the handful of required exterior signs such as accessible entrance symbols. Building names, addresses and logos are exempt, so a pylon or channel letter sign read from the road is outside it, and its letter height is set by legibility for the speed and distance, plus the local sign code. For those, a letter height calculator based on viewing distance is the usual starting point.
Questions
What is the minimum letter height for ADA signs?
For visual characters it depends on mounting height and viewing distance (Table 703.5.5). Between 40 and 70 inches up and read from under 6 feet, 5/8 inch; higher and farther away needs more. Raised characters are fixed at 5/8 to 2 inches.
What is the ADA viewing distance?
The horizontal distance from the characters to the nearest obstruction that stops a reader getting closer, such as a counter, a railing or a planter (703.5.5). In an open corridor there may be no obstruction, and the reader can walk right up to the sign.
Can visual characters on ADA signs be lowercase?
Yes. Visual characters can be uppercase, lowercase or a mix (703.5.2). Only raised characters must be all uppercase.
Do directional signs need to be ADA compliant?
Yes, as visual signs. Signs that give directions to or information about interior spaces must meet 703.5: contrast, non-glare finish, conventional font, size by viewing distance and at least 40 inches up. They do not need raised characters or braille.
Last checked against the source text 2026-09-25. Section numbers refer to the 2010 ADA Standards unless marked otherwise.