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Length Converter

mm, cm, m, km, inches, feet, yards, miles — all at once.

Length conversion is one of the most common calculations in daily life — whether you're buying furniture from an IKEA catalogue with metric dimensions, converting a recipe, checking whether a TV will fit your wall, or comparing vehicle specs between US and European brochures.

100 cm equals
1 m
UnitValue
Millimeters1,000 mm
Meters1 m
Kilometers0.001 km
Inches39.370079 in
Feet3.28084 ft
Yards1.093613 yd
Miles0.000621 mi
Nautical miles0.00054 nmi

Metric vs Imperial: A Practical Guide

The metric system (mm, cm, m, km) is used by virtually every country except the US, Myanmar, and Liberia. The imperial system (inches, feet, yards, miles) is still the daily standard in the US. The UK uses a mix — metric for most official measurements, but miles for road distances and feet/inches for human height.

  • 1 inch = 2.54 cm exactly (defined since 1959)
  • 1 foot = 30.48 cm = 0.3048 m exactly
  • 1 mile = 1.609344 km exactly
  • 1 nautical mile = 1.852 km (exactly) — used in aviation and maritime navigation

Commonly Needed Conversions

These are the conversions people search for most often:

  • 5 feet in cm: 5 ft = 152.4 cm
  • 6 feet in cm: 6 ft = 182.88 cm
  • 5'10" in cm: 177.8 cm
  • 100 km in miles: 62.14 miles
  • 1 mile in km: 1.609344 km
  • 1 meter in feet: 3.281 ft
  • 10 inches in cm: 25.4 cm
  • 100 cm in feet: 3.281 ft

Quick Mental Conversion Tricks

For rough mental math when you don't have a calculator handy:

  • km to miles: multiply by 0.6 (accurate to ~3.5%)
  • miles to km: multiply by 1.6 (accurate to ~0.6%)
  • inches to cm: multiply by 2.5 (accurate to ~1.6%)
  • cm to inches: divide by 2.5 (same accuracy)
  • meters to feet: multiply by 3.3 (accurate to ~0.5%)
  • feet to meters: divide by 3.3

How to Convert Length Units

Two steps to convert any length in one shot.

  1. 1
    Enter the value and select the source unit
    Type your measurement and pick the unit you're converting from (mm, cm, m, km, in, ft, yd, mi, or nautical miles).
  2. 2
    Read all conversions at once
    The table shows every unit simultaneously — no need to convert twice. The primary result shows the most commonly needed conversion for your input.

FAQ

How do I convert inches to centimeters?
Multiply by 2.54. Example: 10 inches = 25.4 cm.
How do I convert feet to meters?
Multiply by 0.3048. Example: 6 ft = 1.8288 m.
How do I convert km to miles?
Multiply by 0.621371. Example: 10 km ≈ 6.21 miles.
How many feet in a meter?
1 meter = 3.28084 feet. Or 1 foot = 0.3048 meters exactly (by definition since 1959).

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