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Length Converter

Convert length and distance between metric and imperial units.

To
Every unit
  • 1,000,000
    Micrometers
    µm
  • 1,000
    Millimeters
    mm
  • 100
    Centimeters
    cm
  • 1
    Meters
    m
  • 0.001
    Kilometers
    km
  • 39.3701
    Inches
    in
  • 3.2808
    Feet
    ft
  • 1.0936
    Yards
    yd
  • 0.0006
    Miles
    mi
  • 0.0005
    Nautical miles
    nmi
  • 1.0570e-16
    Light years
    ly
Precision4 places
Common conversions
LengthEquals
1 inch2.54 cm
1 foot30.48 cm
1 yard0.9144 m
1 mile1.609344 km
1 nautical mile1.852 km
1 cm0.393701 in
1 meter3.28084 ft
1 kilometer0.621371 mi

How to convert length units

  1. Enter a length

    Type the number you want to convert into the field on the left.

  2. Pick the two units

    Choose the unit your value is in, then the unit you want it converted to.

  3. Read the result

    The converted value appears instantly, with every other supported unit listed below it.

  4. Copy what you need

    Copy the headline result, or use the copy button on any row to grab a single unit.

Why use this tool

Eleven units in one place

Micrometers, millimeters, centimeters, meters, kilometers, inches, feet, yards, miles, nautical miles, and light years.

Both directions at once

Pick a from unit and a to unit, then swap them with one tap when you need the reverse conversion.

Exact definitions

An inch is exactly 2.54 cm and a nautical mile is exactly 1,852 m, so imperial and metric results agree to the last decimal.

Adjustable precision

Show whole numbers for a rough sense of scale, or up to six decimal places when small differences matter.

Runs on your device

Every calculation happens in the page as you type. Nothing is uploaded and no account is required.

About this tool

The Length Converter turns one distance into every other common unit at the same time. Enter a value, choose the unit it is measured in, and pick the unit you want. The headline result updates as you type, and a full list underneath shows the same length in micrometers, millimeters, centimeters, meters, kilometers, inches, feet, yards, miles, nautical miles, and light years. There is no convert button to press.

Every unit is defined relative to one meter, so results stay internally consistent no matter which unit you start from. The imperial units use their exact international definitions: an inch is 2.54 cm, a foot is 0.3048 m, a yard is 0.9144 m, and a mile is 1,609.344 m. A nautical mile is exactly 1,852 m, which is why it does not line up neatly with a statute mile. Micrometers and light years sit at each end of the list so the tool still works when the numbers get extreme.

Results that run past a trillion or below a millionth switch to exponent notation instead of sprawling across the row, which is what keeps a light year readable next to a micrometer. The precision slider goes from whole numbers to six decimal places, negative lengths are rejected because they have no physical meaning, and an empty field simply clears the results rather than showing an error.

For single-direction conversions try cm to inches or miles to kilometers. For other dimensions, see the area converter and the volume converter.

Frequently asked questions

How many centimeters are in an inch?
Exactly 2.54. That figure is a definition rather than a measurement, so every inch-to-metric result in this tool is exact rather than rounded.
Why is a nautical mile different from a mile?
A nautical mile is exactly 1,852 meters, based on one minute of latitude, while a statute mile is 1,609.344 meters. One nautical mile is about 1.151 statute miles, which is why sea and air distances read shorter than road distances for the same number.
Can I convert very small or very large lengths?
Yes. Micrometers and light years are both included, and any result past a trillion or below a millionth is shown in exponent notation so it stays readable in the row.
Can I enter a negative length?
No. A length cannot be negative, so negative input is rejected and the results stay blank until you enter zero or a positive number.
Are my numbers sent anywhere?
No. All conversion happens on your device inside the page. Nothing you type is uploaded or stored.

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