81.5 meters to feet

81.5 meters equals 267.38845 feet. To convert meters to feet, multiply the number of meters by 3.280839895.

How to convert 81.5 meters to feet?

Meter

The meter is the base unit of length in the International System of Units, popularly known by its abbreviation SI. The meter is commonly used to measure the sizes of medium- to large-sized objects, and distances between places not too far away. Various tools are available to measure the lengths in meters.

In 1791, the French Academy of Sciences appointed scientists and mathematicians as a part of an initiative to implement a new measurement system. They proposed a decimal-based measurement system and recommended the units of various quantities like length, mass, volume, etc. The unit of length was defined as the ten-millionth of the distance between the North Pole and the equator, passing through Paris, and given the name meter, adopted from the Greek word metron, which means “to measure”. After a geodetic survey done between Dunkirk, France, and Barcelona, Spain, between 1792 and 1798, the final measurement of the length of a meter was realized in 1799, and a platinum bar was created as per this measurement to define the length of a meter. The meter prototype bar was recreated in 1889. This prototype bar was made with 90% platinum and 10% iridium with an X-shaped cross-section to make it more durable and stronger. The definition of meter has been changed several times since its inception, to make it more consistent. The final definition of the meter, which is still in use, was given in 1983. As per this definition, the length of a meter is the same as the distance traveled by the light in a vacuum in 1/299,792,458 seconds. It is important to note that the meter prototype bar made in 1889 was taken as the reference for this definition.

Foot

Foot is a unit of length in the British Imperial System and the United States Customary Unit System. The standard symbol of the foot is ft. It is also denoted by a prime symbol (′).

The unit's name indicates and is believed to be based on the human foot. Since ancient times, the foot has been widely used in European countries and the United States. The length of the foot was different from country to country. Different rulers defined their feet, making the previous one obsolete. This created great confusion for international and intercontinental trade. To overcome this confusion of variation in the unit values, seven countries, including the United States, Canada, New Zealand, South Africa, Australia, and the United Kingdom, signed the International Yard and Pound Agreement in 1959 that defined the yard value as exactly 0.9144 meters. This consequently made the value of the international foot exactly 0.3048 meters.

The foot is used to measure the lengths of objects and small distances. The square foot, the unit derived from the foot, is used to measure the area of a two-dimensional space. To distinguish area and length measurements, the term linear foot is used to indicate the length of the material in feet instead of the area. In aviation, the altitude of flight levels is commonly used in hundred-foot increments. For example, a flight level 320 indicates an altitude of 32000 feet. The dimensions of shipping containers are measured in feet.