You should size out your letters before sizing out your sign. Reverse engineering your sign starts with the size of the letters. The size of the letters determines how far the sign can be view-able.

Let's suppose the speed limit on your street is 45 MPH. And you want your message to be readable for 3 full seconds by passing motorists. A car traveling at 45 MPH for 3 seconds equals a viewing distance of 198 feet. Again, the Lettering Sizing Calculator will automatically give me 2 sizes: The minimum size the letters have to be to be readable And The size recommended for optimal visibility. In this case, the minimum readable size is a 6" tall letter. And the size recommended for optimal visibility is a 20" tall letter.

The viewing distance is how far away you want your sign to be legible. It is very important not to estimate or guess so our calculator can give you to optimum information. Effective signs must be legible and a distance off by 10 feet can make a difference, especially in a moving vehicle.

According the legibility index, a person with 20/20 vision can read a 6" tall letter up to 150' away. The same size letter is considered easily readable from 60' away. The factors that can affect the legibility include the viewing angle, lighting, contrast and colors.

We recommend a minimum of 3 seconds of visibility.

Our letter sizing calculator is based off from research done at The Pennsylvania Transportation Institute, Penn State University and The United States Sign Council (USSC).

Let's say you need a new business sign and you are going to be placing this sign directly on the building. How far away do you want potential clients to be able to read your message? For this example, let's assume you need the sign to be readable at least 60' away. The Letter Sizing Calculator will automatically give me 2 sizes: The minimum size the letters have to be to be legible. And The size recommended for optimal visibility. In this case, the minimum readable size is a 3" tall letter. And the size recommended for optimal visibility is a 6" tall letter. (For added advertising impact, businesses often go even larger).