By Letter Size

How far can you read a 4" tall Letter? Or any other size letter for that matter? To find out the answer, just select the letter size from the drop down list below.

Select letter size

Feet

Maximum Viewable Distance:

Feet

Distance for Easy Readability:

Feet

Distance for Maximum Impact:

By Traveling Size

Let's suppose the speed limit on your street is 45 MPH and you want your message to be readable for 3 full second by passing motorists. How would you know the right letter height? This tool will help you with that. You can also set the street speed limit too!

SPEED
LIMIT

SECONDS OF
VISIBILITY

TOTAL VIEWABLE
DISTANCE

Minimum Readable Letter Size:

Frequently Asked Questions on Letter Sizing Calculator

What size should my letters be?

When it comes to determining the size of your lettering, there are two components to take into consideration: These components are Distance and Speed. Distance applies to how far away you want your sign to be visible. Speed pertains only to signage that will be viewed by passing motorists.

Should I size my sign or letters first?

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.

How can speed affect sign legibility?

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.

What is the viewing distance?

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.

How far is a 6" letter legible?

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.

What is the recommended amount of time a sign should be legible to make an impact?

We recommend a minimum of 3 seconds of visibility.

What are these calculators information based on?

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).

How does the sizing calculator simplify the math?

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).