ADA Tactile Letters: Height, Stroke, Spacing and Mounting Height

A room sign can look perfect and still fail inspection by a sixteenth of an inch. Raised (tactile) letters are read by fingers, so the 2010 ADA Standards for Accessible Design, section 703.2, set tight rules for their size, shape and spacing. Here they are, with the numbers a shop actually needs.

1. Height: 5/8 inch to 2 inches

Raised characters must be 5/8 inch minimum and 2 inches maximum, measured on the uppercase letter I. Measure the I, not the O or a lowercase letter, because rounded letters overshoot the baseline.

There is one federal exception: where a sign carries separate raised and visual characters with the same information, the raised characters may be as small as 1/2 inch. California does not allow this exception.

2. Uppercase, sans serif, nothing fancy

• All raised characters are uppercase.
• Sans serif only. No italic, oblique, script or highly decorative fonts.
• Proportions: the width of the uppercase O must be 55 to 110 percent of the height of the uppercase I (California: 60 to 110 percent). Very condensed fonts fail this test.

Arial, Helvetica and similar fonts usually pass. Test any brand font before you promise it to the client.

3. Raised 1/32 inch

Characters stand 1/32 inch minimum above the background. Most photopolymer and applied-letter systems meet this; check the spec of the material you use.

4. Stroke thickness: 15 percent maximum

The stroke of the uppercase I may be at most 15 percent of the character height. For 1-inch letters, that is a stroke of 0.15 inch or thinner. Bold weights of some fonts are too heavy.

5. Letter spacing

For letters with a square-cut (rectangular) profile, the space between neighboring characters is 1/8 inch minimum and 4 times the stroke width maximum. For rounded or beveled profiles, the rule is 1/16 inch minimum at the base and 1/8 inch minimum at the top. Measure at the closest point between letters, not center to center.

Raised characters should also stay 3/8 inch away from raised borders and decorative elements.

6. Line spacing

Between lines of raised text, the baseline-to-baseline distance is 135 to 170 percent of the character height. For 1-inch letters: 1.35 to 1.70 inches.

7. Braille goes below

Every raised character message is repeated in contracted (Grade 2) braille, placed below the text, at least 3/8 inch away from it. If the text has several lines, the braille goes below all of them. See our braille dimensions guide.

8. Mounting height and location

• Height: the baseline of the lowest tactile character (usually the bottom braille line) at 48 inches minimum above the floor, and the baseline of the highest raised character at 60 inches maximum.
• Location: beside the door on the latch side. At double doors with one active leaf, on the inactive leaf; with two active leaves, to the right of the right-hand door.
• Clear floor space: an 18 x 18 inch clear space centered on the characters, outside the swing of the door from closed to 45 degrees open.

9. Contrast and finish

Characters and background must be non-glare (matte or eggshell) and contrast with each other, light on dark or dark on light. Many projects now also ask for a measured contrast based on LRV values; check the specification.

Quick reference

Lay it out right the first time

Our free ADA Sign Maker checks letter height, braille position and margins as you type and exports SVG and DXF cut files. Inside SignAcctPro, the same check runs on every room sign and the sign drops straight into the client's proof and quote. For large facility packages, Sign Desk draws the full schedule overnight.

Signs are designed to ADA guidelines. Always confirm the current local code and the project specifications before fabrication.