Convert Length from Us Survey Foot to Kilometer (ft-us to km)

US Survey Foot to Kilometer Conversion Formula

To convert from US Survey Foot (ft-us) to Kilometer (km), use the following formula:

With $\frac{1}{3.28084}$ is the ratio between the base units Meter (m) and Foot (ft).

Example

Let's convert 5 US Survey Foot (ft-us) to Kilometer (km).

Using the formula:

Therefore, 5 US Survey Foot (ft-us) is equal to $0.0015240029992319040246$ Kilometer (km).

What is a US Survey Foot (ft-us)?

The US Survey Foot is a unit of length historically used for land surveying in the United States.

It is very close in length to the international foot, equaling approximately 1.000002 international feet (ft). The plural form is US Survey Feet.

Where Did the US Survey Foot Come From?

The origin of the US Survey Foot dates back to the Mendenhall Order of 1893. This order defined the relationship between the meter and US customary units.

It established that 1 meter is precisely equal to 39.37 inches. From this relationship, the US Survey Foot was derived, defined as 1200/3937 meters.

This definition differs slightly from the international foot, which was established in 1959 and is defined as exactly 0.3048 meters.

Why Was the US Survey Foot Replaced?

To simplify measurements and prevent confusion, the National Institute of Standards and Technology (NIST) and the National Geodetic Survey (NGS) made a critical change.

They officially retired the U.S. Survey Foot on December 31, 2022.

Surveying and mapping applications in the United States will now use the international foot. This critical change helps unify the National Spatial Reference System (NSRS) and prevents costly errors in large-scale projects.

Why Did This Small Difference Cause Big Problems?

While the difference between a US Survey Foot and an international foot is minuscule—only about two parts per million—it becomes significant over large distances.

For every mile, the discrepancy adds up to approximately 1/8 inch.

This minor error may not be significant for a backyard fence. However, for massive construction projects and infrastructure development, such as bridges that cross state lines, the accumulated error can lead to severe misalignments and costly mistakes.

What is a Kilometer (km)?

A kilometer (km) is a unit of length in the metric system, equal to 1,000 meters.

The plural form is kilometers.

Where Does the Word "Kilometer" Come From?

The term "kilometer" is composed of two parts: the metric unit "meter" and the Greek prefix "kilo," which comes from the word "khilioi," meaning "thousand."

Thus, a kilometer translates to one thousand meters.

This concept is a fundamental aspect of the decimal-based metric system, established in France during the 1790s. The logical, prefix-based nature of the metric system simplifies conversions, which is a key reason for its widespread adoption.

Which Countries Use the Kilometer?

The kilometer is the official unit of measurement for geographical distance in the vast majority of countries worldwide.

Only a few nations still primarily use the mile for road signage and navigation, most notably:

• The United States
• The United Kingdom
• Liberia
• Myanmar

For international travel, science, and sporting events like marathons and the Olympics, the kilometer is the universally accepted standard.

How Far Is a Kilometer? Examples You Can Visualize

To understand how far a kilometer is, consider these real-world examples:

• Walking one kilometer at an average pace takes about 10 to 12 minutes.
• The Earth's circumference at the equator is approximately 40,075 kilometers.
• In terms of astronomical distances, the Moon is, on average, about 384,400 kilometers away from Earth.

This consistent unit of measurement makes it easy to compare everything from everyday travel to distances in space.

What is the imperial system?

What is the metric system?

US Survey Foot to Kilometer Conversion Table

Here are some quick reference conversions from US Survey Foot (ft-us) to Kilometer (km):