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Converters

Convert between metric and imperial lengths

Length converter takes a number, the unit it is in, and shows the same length in every unit at once: millimeters, centimeters, meters, kilometers, inches, feet, yards, miles and nautical miles. Engineers and builders in mixed-metric workplaces use it to translate measurements in either direction. Choose the starting unit in "From" and type the value; the factors are the exact international ones (1 inch is 25.4 mm, 1 mile is 1609.344 m), and results are shown to ten significant digits.

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How to use Length Converter

  1. Open Length Converter in the Toolbox101 app.
  2. Pick the unit your number is in with From (meters by default).
  3. Type the length into the Value box, for example 42.195.
  4. Read every unit in the Output box, one per line.
  5. Click Copy to keep the converted values for your drawing, order or spec.

Worked example

Length Converter returns the output below for this combination.

Settings

From: Kilometers (km)

Input

42.195

Output

Millimeters: 42195000 mm
Centimeters: 4219500 cm
Meters: 42195 m
Kilometers: 42.195 km
Inches: 1661220.472 in
Feet: 138435.0394 ft
Yards: 46145.01312 yd
Miles: 26.21875746 mi
Nautical miles: 22.78347732 nmi

Check it yourself: open Length Converter and enter the same settings and input.

Frequently asked questions

Can I convert feet or inches to meters?

Yes. Set From to the unit you have and type the number; the meters row is one of the lines in the output. Starting from Feet, a value of 6 gives 1.8288 m, and from Inches, 5 gives 0.127 m.

Are the conversion factors exact?

The imperial ones are exact by definition: the international inch is 25.4 mm, so one foot is 0.3048 m, a yard 0.9144 m and a mile 1609.344 m. The nautical mile is 1852 m. The only rounding is in the display, which shows ten significant digits.

Why do some results show many decimals or an exponent?

Every unit is shown, from millimeters to miles, so tiny or huge values appear in the same list: a few meters is a minuscule fraction of a mile. Numbers are written with up to ten significant digits, and very small or very large ones switch to exponent notation such as 1e-7.

What about decimals and scientific notation in the input?

Both work: 3.5, .5 and 1.2e3 are accepted, and spaces or underscores inside the number are ignored. Anything else, a unit written after the number for instance, gets a message asking for a plain number.

Use Length Converter now

Open Length Converter in the app

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