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To convert from Inch (in) to US Survey Foot (ft-us), use the following formula:
Let's convert 5 Inch (in) to US Survey Foot (ft-us).
Using the formula:
Therefore, 5 Inch (in) is equal to US Survey Foot (ft-us).
Here are some quick reference conversions from Inch (in) to US Survey Foot (ft-us):
| Inches | US Survey Feet |
|---|---|
| 0.000001 in | ft-us |
| 0.001 in | ft-us |
| 0.1 in | ft-us |
| 1 in | ft-us |
| 2 in | ft-us |
| 3 in | ft-us |
| 4 in | ft-us |
| 5 in | ft-us |
| 6 in | ft-us |
| 7 in | ft-us |
| 8 in | ft-us |
| 9 in | ft-us |
| 10 in | ft-us |
| 20 in | ft-us |
| 30 in | ft-us |
| 40 in | ft-us |
| 50 in | ft-us |
| 100 in | ft-us |
| 1000 in | ft-us |
| 10000 in | ft-us |
For all Length converters, choose units using the From/To dropdowns above.
An inch (in) is a standard unit of length used in the imperial and United States customary systems.
It is most commonly known as 1/12 of a foot. The plural form is "inches."
For a quick inch definition, here are the most important conversions:
The history of the inch goes back centuries. The word "inch" itself originates from the Latin word uncia, meaning "one-twelfth," which highlights its relationship to the larger unit of a foot.
Early definitions were often based on natural reference points. For a long time, an inch was widely considered to be the width of a man's thumb at the base of the nail.
To create a more reliable standard, 14th-century English King Edward II officially defined the inch as the length of three grains of barley placed end to end.
While the inch is an imperial unit, its official modern definition is based on the metric system.
Since 1959, an international agreement has defined the inch as exactly 2.54 centimeters (or 25.4 millimeters).
This universal standard, agreed upon by the United States, the United Kingdom, and other nations, ensures that the inch has a precise and globally recognized value.
This consistency is crucial for international trade, engineering, and science.
In fields that require extreme accuracy, such as engineering and machining, the inch is often divided into even smaller parts.
One-thousandth of an inch (1/1000 or 0.001 inches) is commonly known as a "thou" or a "mil."
Although very small, this unit is crucial for defining tolerances in the manufacture of engine components, electronic devices, and other precision equipment, where minute differences can have significant effects.
By comparison, a standard piece of paper measures roughly 2–4 thou in thickness.
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.
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.
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.
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.