What is foot?

A foot is a unit of length in imperial and US customary systems equal to 12 inches. It is commonly used in construction, architecture, body height measurements, and aviation for altitude references.

Real-world uses

Feet are the primary unit for building dimensions, room sizes, and ceiling heights in the United States. Aviation uses feet for altitude worldwide (e.g., cruising at 35,000 ft). Human height in the US and UK is commonly expressed in feet and inches.

History

The foot has been used since ancient civilizations, with varying lengths based on the local king's foot. The modern international foot was defined in 1959 as exactly 0.3048 metres, replacing slightly different US and British survey definitions.

Common mistakes

Using an apostrophe for feet (6') and confusing it with the prime symbol. Also, people often round 1 foot to 30 cm instead of the correct 30.48 cm, leading to cumulative errors in construction.

What is metre?

The metre is the SI base unit of length. It is used globally in science, engineering, geography, and everyday measurement as the standard reference for distance.

Real-world uses

The metre is the standard unit for everyday measurements worldwide, from room dimensions and furniture sizes to athletic track events like the 100 m sprint. Engineers, architects, and scientists use it as the fundamental length reference in the SI system.

History

Originally defined in 1793 during the French Revolution as one ten-millionth of the distance from the North Pole to the equator along a meridian through Paris. Since 1983, it is defined by the speed of light in vacuum.

Common mistakes

Confusing "meter" (the measuring device) with "metre" (the unit of length) in British English. Also, people sometimes incorrectly assume 1 metre equals exactly 3 feet; it is actually about 3.281 feet.

When is this conversion used?

Converting between foot and metre is common when working across metric and imperial systems, such as international trade, travel between countries with different measurement standards, or following instructions from a different region. This conversion is frequently needed in construction, architecture, and real estate where building codes may specify dimensions in one system while materials are sold in another.

Worked examples

1 foot = 0.3048 metre

1 metre = 1 metre

How to convert foot to metre

To convert foot to metre, multiply the value by 0.3048.

To convert metre back to foot, multiply by 3.2808399.

Measurement standards

The metre is one of seven SI base units, maintained by the International Bureau of Weights and Measures (BIPM). Since 2019, it is defined by fixing the numerical value of the speed of light in vacuum to exactly 299,792,458 metres per second.

Did you know?

A human hair is roughly 70 micrometres wide, while a single gold atom measures about 0.144 nanometres in diameter — meaning you could line up nearly half a million atoms across the width of one hair.

Quick reference: foot to metre

footmetre
0.10.03048
0.50.1524
10.3048
20.6096
51.524
103.048
257.62
5015.24
10030.48
25076.2
500152.4
1,000304.8

Common values

footmetre
Height of a door6.88976378 foot2.1 metre
Basketball court length91.86351706 foot28 metre
Football field (soccer)344.48818898 foot105 metre
Marathon distance138,435.03937008 foot42,195 metre
Altitude of a cruising airplane35,000 foot10,668 metre