There's one other foot measurement - the Indian survey foot. Furthermore, the legislation on the survey foot varies between the 50 states:Ģ4 states have legislated that surveying measures should be based on the US survey footĨ states have decided that it should be made on the basis of the international footġ8 states haven't specified the conversion factor from metric unitsīut don't worry too much - if you need the conversion for your everyday land surveying or real estate transactions, the difference is really negligible for short distances (< 1 mile), so it doesn't matter which definition you settle on. It's important because the difference is negligible if we measure relatively small objects, but it grows significantly if we begin measuring hundreds of thousands of feet, as in mapping or using state plane coordinate system (SPCS).

mĪs you can see, it looks like a really tiny difference - something changes at the seventh decimal place! Which is a difference of ≈0,609 μm ≈ 609 nm, comparing the one type of a foot to another.

The US survey foot is almost identical in measure to the international foot. The international foot measure corresponds to a human foot with a shoe size of 13 (UK) or 14 (US male). Used widely in many applications, it's equal to 0.3048 m:ġ international foot ≡ 0.3048 m, where we used the ≡ sign to emphasize it's equal to exactly this value In the US, two types of feet are used on a daily basis: the international foot and the survey foot:Īlso named the standard foot it's the one standardized in the 1950s. As yard was defined, the foot could be calculated as well. Since then, yard in the United States and countries in the British Commonwealth is equal to exactly 0.9144 meters. The final agreement on the foot length came much later, in 1959, when the international yard and pound agreement was accepted. Then Edward II of England introduced some kind of standardization by introducing the statute foot which was 10⁄11 of the old foot. The feet definition varied from region to region, city to city, later even the kings changed the measure according to their desire - e.g., Henry I was said to have ordered a new standard based upon his arm. In England, the foot measure also changed through the ages - it started from Roman standards, then Belgic Celts foot of 13.2 inches or Welsh foot came and went. acoustics - microphones' and loudspeakers' diameters

some sport equipment uses the values in inches e.g.

screen resolution in pixels per inch (for more information, head to our ppi calculator).

screen sizes of smartphones, monitors, TVs, (specifically, the diagonals of rectangular screens).

What can be measured in inches - not only in the US, but worldwide? Height, length, width may be measured in inches, also many sizes are expressed in units derived from inches (e.g.

On a daily basis, inches are used in US, UK, Canada and other countries which were formerly part of the British Empire. One inch is also equal to 1⁄36 yard, 1⁄12 of a foot or 1⁄63360 of a mile. Inch definition varied through the ages but during the 1950's an international standard was accepted, and since then the inch is equal to exactly 2.54 centimeters. In the 14th century, the inch was defined by the king of England as three grains of barley, dry and round, placed end to end, lengthwise. Norwegian, Afrikaans, Italian or French, an inch is derived from the word for thumb or, in some cases, it's the same word. The measure comes from - by some definitions - the width of a human thumb. The inch (abbreviate as in or ') is a unit of length in Imperial / the US metric system.

Measurement unit conversion