Use this chart to help you determine the appropriate letter size when choosing building letters.
This letter visibility chart is based upon information provided by Pennsylvania Transportation Institute, Penn State University and the United States Sign Council (USSC). c1998. Calculations based on externally (or naturally) lit sign with all upper case Helvetica letters utilizing optimal negative space. Factors that may affect required letter size are: color scheme, font selection, traffic and weather conditions, or sign standoff.
| Viewing Distance | Minimum Letter Height |
| 100 ft | 4" |
| 250 ft | 10" |
| 360 ft (city block) | 16" |
| 500 ft | 22" |
| 750 ft | 33" |
| 1000 ft | 43" |
| 1320 ft (1/4 mile) | 57" |