Length Converter

Convert between different length units instantly. Support for metric, imperial, nautical, and astronomical units with precise calculations and comprehensive conversion tables.

Length Converter

Quick Reference

Common Metric Conversions

1 km = 1,000 m
1 m = 100 cm
1 cm = 10 mm

Common Imperial Conversions

1 mile = 5,280 feet
1 yard = 3 feet
1 foot = 12 inches

Metric to Imperial

1 inch = 2.54 cm
1 foot = 30.48 cm
1 mile = 1.609 km

How to Use the Length Converter

  1. Enter Value: Input the length value you want to convert
  2. Select From Unit: Choose the unit you're converting from using the dropdown menu
  3. Select To Unit: Choose the unit you want to convert to
  4. Swap Units: Use the swap button to quickly reverse the conversion
  5. View Results: See the converted value and conversion formula
  6. Check All Conversions: View your input converted to all available units

Supported Length Units

Metric Units

  • • Nanometers (nm)
  • • Micrometers (μm)
  • • Millimeters (mm)
  • • Centimeters (cm)
  • • Meters (m)
  • • Kilometers (km)

Imperial Units

  • • Mils (mil)
  • • Inches (in)
  • • Feet (ft)
  • • Yards (yd)
  • • Miles (mi)

Nautical Units

  • • Nautical Miles (nmi)

Astronomical Units

  • • Astronomical Units (au)
  • • Light Years (ly)

Conversion Examples

Common Everyday Conversions

Height Conversion
6 feet = 182.88 centimeters
5'10" = 177.8 cm
Distance Conversion
1 mile = 1.609 kilometers
100 meters = 328.084 feet
Small Measurements
1 inch = 2.54 centimeters
10 mm = 1 centimeter

Professional & Scientific

Engineering
0.001 inches = 25.4 micrometers
1 mil = 0.0254 millimeters
Navigation
1 nautical mile = 1.852 kilometers
1 nautical mile = 6,076.12 feet
Astronomy
1 AU = 149,597,870.7 km
1 light year = 9.46 × 10¹⁵ meters

Frequently Asked Questions

How accurate are the conversions?

Our length converter uses precise conversion factors defined by international standards. Results are accurate to 10 decimal places for most conversions, which is more than sufficient for virtually all practical applications.

What's the difference between metric and imperial units?

Metric units are based on powers of 10 (decimal system) and are used worldwide. Imperial units (feet, inches, miles) are primarily used in the United States and are based on historical measurements. Metric is generally easier to calculate with due to its decimal nature.

Can I convert very large or very small measurements?

Yes! Our converter handles everything from nanometers to light years. For very large or small numbers, results are displayed in scientific notation for clarity and precision.

What is a nautical mile?

A nautical mile is based on the circumference of the Earth and equals one arc minute of latitude. It's approximately 1.852 kilometers or 6,076 feet, and is used in marine and aviation navigation.

How do I convert feet and inches to centimeters?

First convert everything to inches (multiply feet by 12, then add inches), then multiply by 2.54 to get centimeters. For example: 5'10" = (5×12)+10 = 70 inches = 70×2.54 = 177.8 cm.

What are astronomical units used for?

Astronomical units (AU) represent the average distance from Earth to the Sun, about 150 million kilometers. Light years measure the distance light travels in one year. These units make it easier to express the vast distances in space.

Related Calculators

Weight Converter

Convert between kilograms, pounds, ounces, grams, and other weight units.

Try calculator

Area Converter

Convert between square meters, square feet, acres, hectares, and more.

Try calculator

Volume Converter

Convert between liters, gallons, cubic meters, fluid ounces, and more.

Try calculator