Convert feet to inches

Symbol

The foot is represented by the symbol ‘ft’ or often approximated by an apostrophe. For example, 5 feet is sometimes denoted as 5’.

Description

The Foot is a unit of length in the British imperial and United States customary systems of measurement. In both cases, one foot is equal to 12 inches.

For yard to foot calculations, one yard comprises of three feet. The standard measurement of a foot is exactly 0.3048 meters, which is equivalent to 304.8 millimeters. So for foot to meter conversion, multiply foot by 0.3048. 

Following that, there are 3.281 feet in a meter. While converting ft to cm, note that there are 0.0328 feet in a centimeter. So, one foot is equal to 30.48 centimeters. 

The measurement of a United States survey foot is exactly 1200 ⁄3937 meters or approximately 0.30480061 m. It is used for mapping and surveying. It is exactly 1,000,000/999,998 times the international foot which means that it is larger by 610 nm or nanometer.

History

The Old English word "fot" is where the word "foot" (meaning "terminal part of the leg of a vertebrate animal") came from.

Historically, the "foot" was a part of many regional systems of units, such as the Greek, Roman, Chinese, French, and English systems. The first recorded standard foot measure comes from Sumer, where a definition is given in a statue of Gudea of Lagash from around 2575 BC. 

Use

Feet is generally used for measuring height such as floor height, human height, short distances, elevation etc.

Symbol

The inch is represented by the letters in or a double straight quotation mark (“). For example, 5 inches is written as 5 in or 5”. 

Description

Inch is one of the smaller units of length measurement in the British imperial and the United States customary system of measurement. This estimation is thought to have derived from the width of the human thumb. The word ‘inch’ was derived from the Roman word "uncia" (twelfth).

In the past, there have been multiple standards regarding the exact measurement of an inch. However, with the adoption of the international yard during the 1950s and 1960s, the inch has been based on the metric system and defined as exactly 25.4 mm.

So it is quite easy to convert centimeter to inch or in to cm. According to the international scales, there are 2.54 centimeters in an inch. So inversely, an inch is equivalent to 1/2.54 centimeters.

For inch to foot conversion, note that one foot is equal to 12 inches. So, while doing ft to in conversion just divide the inch digits by 12 since an inch is equivalent to 1/12 feet. For in to yard conversion, an inch is equivalent to 1/36 yard.

History

Inch was used in the Textus Roffensis in 1120. It is the only surviving manuscript from the Laws of Æthelberht (which dates to the early 7th century). It is the earliest known reference to the inch in England. 

King Edward II of England proclaimed in 1324 that one inch was equivalent to three barley grains put end to end lengthwise. But as the barley grains' size could not be fixed, there was a possibility of having error in standardizing inch by this defintion. Actually before the establishment of the international yard and pound, numerous definitions were used for inch.

In 1912, US and UK followed different definitions of inch measurement. Carl Edvard Johansson then reached a compromise. He produced gauge blocks with a nominal size of 25.4 mm that were accurate to within a few parts per million of both official standards. Because of the popularity of Johansson's blocks, several countries began using 25.4 mm as the inch between 1930 and 1964. It became known as the industrial inch. And this has since become the new official measurement of the inch. 

Use

Inch is mostly used in countries following the FPS (foot-pound-second) system of units. It is sometimes used for measuring small dimensions such as mobile display or electronic parts.