Metric Converter

1. What units are supported?
2. Difference between Imperial and Metric units
3. Metric conversion examples
4. Unit conversion tables

    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

While using a metric converter for units of the same system is quite common, it is even more useful when one needs to convert a metric unit of length to an imperial unit of length. 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. Still, a lot of lengths are measured in one of the two systems so conversion between them is necessary.

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 tool 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:

Formula:
miles * 1.609344 = km
Calculation:
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:

Formula:
ft / 3 = yd
Calculation:
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:

Formula:
yd * 0.9144 = m
Calculation:
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 metric 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:

Meters to feet conversion table:

Inches to cm conversion table:

While these length conversion tables are useful, it is much easier to use software when possible.