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.

What is inch?

An inch is a unit of length in imperial and US customary systems equal to 1/12 of a foot. It is widely used for screen sizes, display resolutions, pipe diameters, and small-scale measurements in everyday contexts.

Real-world uses

Inches are used throughout the United States, Canada (partially), and the UK for screen sizes, pipe diameters, lumber dimensions, and screw/bolt specifications. Display sizes for monitors, TVs, and phones are universally quoted in diagonal inches.

History

The inch has ancient origins, traditionally defined as the width of a man's thumb or three barleycorns laid end to end. It was standardized internationally in 1959 as exactly 25.4 mm, reconciling slight differences between British and American definitions.

Common mistakes

Assuming inch fractions are decimal—1/8 inch is 0.125 inches, not 0.18. Also, confusing nominal lumber sizes (a "2x4" is actually 1.5 × 3.5 inches) with actual inch measurements.

When is this conversion used?

Converting between metre and inch 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. Screen sizes, paper dimensions, and clothing measurements often require converting between centimetres and inches, especially when shopping internationally.

Worked examples

1 metre = 39.37007874 inch

1 inch = 0.0254 metre

How to convert metre to inch

To convert metre to inch, multiply the value by 39.37007874.

To convert inch back to metre, multiply by 0.0254.

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: metre to inch

metreinch
0.13.93700787
0.519.68503937
139.37007874
278.74015748
5196.8503937
10393.7007874
25984.2519685
501,968.50393701
1003,937.00787402
2509,842.51968504
50019,685.03937008
1,00039,370.07874016

Common values

metreinch
Height of a door2.1 metre82.67716535 inch
Basketball court length28 metre1,102.36220472 inch
Football field (soccer)105 metre4,133.85826772 inch
Marathon distance42,195 metre1,661,220.47244094 inch
Altitude of a cruising airplane10,668 metre420,000 inch