Letter Height Visibility Chart. Signazon.com’s letter visibility chart shows the maximum reading distance for your sign to make the best impact, as well as the overall readable distance. A good rule of thumb is every 1 inch of letter height provides 10 feet of readability with the best impact.

Signazon.com’s letter visibility chart shows the maximum reading distance for your sign to make the best impact, as well as the overall readable distance. For example, 3” tall letters make the best impact within 30’; A good rule of thumb is every 1 inch of letter height provides 10 feet of readability with the best impact.