Metric Converter

Use this free online converter to easily convert between units for measuring length. Metric and imperial units for measuring dimensions and distances are supported.

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What units are supported?

This versatile unit converter supports conversions between imperial units, between metric units, as well as converts between metric and imperial, and vice versa. You can convert units used for measuring tiny distances such as millimeters (mm), micrometers (μm), and nanometers (nm), small distances like inches (in), feet (ft), yards (yd), centimeters (cm), decimeters (dm), and meters (m) as well as larger distances: miles (mi), kilometers (km), and the more rarely used nautical miles (M) and leagues (lea).

The online metric converter uses definitions for the units as they are established with international treaty in 1959 and as defined by the International System of Units (SI) [1], whose definitions are followed universally around the world. It is also in accord with the ISO standards for quantities and units [2]. The symbol convention is the one defined by SI. In some locations it may not be followed, e.g. the same symbol: "m", may be used for both miles and meters, causing potential confusion.

The output is accurate to nine decimal places, which is more than enough for most applications where a unit converter is needed, for example in engineering, architecture, sciences, land demarcation, construction works, travel / transportation calculations, etc.

Difference between Imperial and Metric units

Since 1959 both metric and imperial units are defined using the standard meter as a base unit. The difference remains in their history - with imperial methods having a much longer history than the modern metric system, and in their application. Imperial units are officially used in the United States, United Kingdom, and a couple of other countries in the world, while the metric system is official in the rest of the world.

Some occupations retain the use of imperial units, e.g. naval and air navigation and demarcation, and they are also standardly used in some niche markets, e.g. the consumer electronics market, and especially screen/display/monitor sizes are often expressed in inches, instead of centimeters or millimeters.

With those exceptions, the utility and ease of use of the metric system makes it the preferred choice in everyday life, science, and engineering.

Curious fact: one of the costliest mistakes that happened due to incorrect usage of metric and imperial units in September 1999. In it, NASA lost a $125 million Mars orbiter, because a Lockheed Martin engineering team used English units of measurement while the agency's team used the more conventional metric system for a key spacecraft operation, according to a review finding released a week after the incident [3].

Metric conversion examples

There are many possible conversions between the metrics supported in our metric converter above. Consequently, there are many unit pairs we can give examples for, but we have chosen some of the most popular.

Miles to Kilometers conversion example

Sample task: convert 5 miles to kilometers. Solution:

miles * 1.609344 = km
5 miles * 1.6093 = 8.046720 km
End result:
5 miles is equal to 8.046720 km

Feet to Yard conversion example

Sample task: convert 60 feet to yards. Solution:

ft / 3 = yd
60 ft / 3 = 20 yd
End result:
60 ft is equal to 20 yd

Meters to Yards conversion example

Sample task: convert 25 yards to meters. Solution:

yd * 0.9144 = m
25 yd * 0.9144 = 22.86 m
End result:
25 yd is equal to 22.86 m

Unit conversion tables

Below are conversion tables for some of the most used pairs of units you can use for quick reference. Using our converter above you can construct your own tables, if you need a quick reference somewhere you do not have internet access. Our converter also works offline, so as long as the page is cached in your browser, you can use it freely.

Miles to km conversion table:

miles to km conversion table
miles km
1 miles 1.609344 km
2 miles 3.218688 km
3 miles 4.828032 km
4 miles 6.437376 km
5 miles 8.046720 km
6 miles 9.656064 km
7 miles 11.265408 km
8 miles 12.874752 km
9 miles 14.484096 km
10 miles 16.093440 km
20 miles 32.186880 km
30 miles 48.280320 km
40 miles 64.373760 km
50 miles 80.467200 km
60 miles 96.560640 km
70 miles 112.654080 km
80 miles 128.747520 km
90 miles 144.840960 km
100 miles 160.934400 km

Meters to feet conversion table:

m to ft conversion table
m ft
1 m 3.280840 ft
2 m 6.561680 ft
3 m 9.842520 ft
4 m 13.123360 ft
5 m 16.404199 ft
6 m 19.685039 ft
7 m 22.965879 ft
8 m 26.246719 ft
9 m 29.527559 ft
10 m 32.808399 ft
20 m 65.616798 ft
30 m 98.425197 ft
40 m 131.233596 ft
50 m 164.041995 ft
60 m 196.850394 ft
70 m 229.658793 ft
80 m 262.467192 ft
90 m 295.275591 ft
100 m 328.083990 ft

Inches to cm conversion table:

in to cm conversion table
in cm
1 in 2.54 cm
2 in 5.08 cm
3 in 7.62 cm
4 in 10.16 cm
5 in 12.70 cm
6 in 15.24 cm
7 in 17.78 cm
8 in 20.32 cm
9 in 22.86 cm
10 in 25.40 cm
20 in 50.80 cm
30 in 76.20 cm
40 in 101.60 cm
50 in 127 cm
60 in 152.40 cm
70 in 177.80 cm
80 in 203.20 cm
90 in 228.60 cm
100 in 254 cm


[1] NIST Special Publication 330 (2008) - "The International System of Units (SI)", edited by Barry N.Taylor and Ambler Thompson

[2] International Organization for Standardization (1993). ISO Standards Handbook: Quantities and units (3rd edition). Geneva: ISO. ISBN 92-67-10185-4.

[3] CNN (1999) - "Metric mishap caused loss of NASA orbiter"

Cite this converter & page

If you'd like to cite this online converter resource and information as provided on the page, you can use the following citation:
Georgiev G.Z., "Metric Converter", [online] Available at: URL [Accessed Date: 26 Apr, 2019].