One of the things that should always be considered when ordering ADA signs to be made is the character or letter sizes of these signs. For you to get it right, you have to know how high the sign will be posted. You will also need to know how far from these signs people will be standing to read them.

Sign mounting will help you determine the correct character height for these signs to be ADA compliant. Minimum character size for ADA compliant signs is 5/8” but, this is only ideal if a sign is to be read by someone six feet away and when the sign is mounted at 40” to 70” from the floor. When the signs are to be read from higher vantages and from longer distances, the size of the characters should also be adjusted.

For signs that are mounted at a height of 40” to 70” high, the character size for these signs increase at .25” increments for every two feet increase in readability distance. For example, if your sign can only be read from 8 feet away, the character height should be 1” high. If the readability distance is 9 to 10 feet, the character sizes on your ADA sign should be 1.25” high.

The same goes for signs that are mounted between 70” to 120” high as well as signs that are mounted at twenty feet or higher. Increments in minimum character height are .25” for every 2 feet increase with the minimum character size for signs that can be seen from 15 feet away being 2” high. Signs that are mounted at minimum heights of 20 feet usually have characters that measure at least 3” high.

To calculate how big the characters should be for a sign that is readable at 30 to 31 feet away, simply add .25” to every 2 feet added to 15 feet. This would mean that a sign readable at 30 to 31 feet away should have a minimum character height of 4”, as per the .25” increase every 2 feet of distance calculation. Signs that are mounted at heights of 30 to 31 feet should have characters that measure at least 4” to 4.25” high and signs at 42 to 45 feet should have characters that are at least 6” in size.