Length Converter - Free Length Unit Converter & Calculator
Free length converter to convert between meters, feet, inches, kilometers, miles, and more. Switch between metric and imperial length units instantly. Supports 20+ length units including nautical miles, light years, astronomical units, and parsecs. Perfect for construction, engineering, science, and everyday measurements.
Last updated: January 23, 2026
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Conversion Results
Metric Units
Millimeters
100,000 mm
Centimeters
10,000 cm
Meters
100 m
Kilometers
0.1 km
Imperial/US Units
Inches
3,937.0079 in
Feet
328.084 ft
Yards
109.3613 yd
Miles
0.062137 mi
Other Units
Nautical Miles
0.053996 nmi
Conversion Tips:
- • 1 meter = 3.281 feet = 39.37 inches
- • 1 kilometer = 0.6214 miles
- • 1 inch = 2.54 centimeters exactly
- • 1 mile = 1.609 kilometers
- • 1 nautical mile = 1.852 kilometers
Length Converter Features
Unit categories
Metric, Imperial, Astronomical
Convert between millimeters, centimeters, meters, kilometers, inches, feet, yards, miles, nautical miles, light years, and more
Speed
Instant calculations
See results in all units immediately as you enter or change values
Precision
Based on international standards
Uses exact conversion factors from NIST and international standards
Use cases
Blueprints, Measurements, Planning
Convert measurements for construction plans, engineering drawings, and building projects
Astronomical units
Light Years, Parsecs, AU, Sun Radii
Convert astronomical distances for scientific calculations and space measurements
Applications
Height, Distance, Travel, DIY
Convert measurements for height, distance, travel planning, and home improvement projects
Quick Example Result
For a length of 100 meters:
Feet
328.1 ft
Inches
3,937 in
How Our Length Converter Works
Our length converter uses meters as the base unit for all conversions. When you enter a length value in any unit, the calculator first converts it to meters, then displays the equivalent in all other supported units. This ensures accurate conversions across all measurement systems.
Common Conversion Formulas
Meters to Feet:feet = meters × 3.281Inches to Centimeters:centimeters = inches × 2.54Kilometers to Miles:miles = kilometers × 0.6214All conversions are based on international standards. For example, 1 inch = 2.54 cm exactly, and 1 meter = 3.28084 feet (approximately 3.281 feet).
Understanding Length Units
Length units are organized into three main categories:
Metric System
Based on powers of 10. Common units: millimeters (mm), centimeters (cm), meters (m), kilometers (km).
1 km = 1,000 m = 100,000 cm
Imperial/US System
Used primarily in the United States. Common units: inches (in), feet (ft), yards (yd), miles (mi).
1 mi = 1,760 yd = 5,280 ft
Astronomical Units
Used for very large distances. Includes: light years (ly), parsecs (pc), astronomical units (au).
1 ly ≈ 9.461 × 10¹⁵ m
Practical Applications
This converter is essential for various real-world applications:
Construction & Building
Convert measurements for construction plans, blueprints, and building projects. Essential when working with both metric and imperial measurements in construction and engineering.
Travel & Navigation
Convert distances for travel planning, navigation, and route calculations. Convert between kilometers and miles for road trips, or use nautical miles for maritime navigation.
Science & Research
Convert measurements for scientific calculations, research, and data analysis. Use astronomical units for space measurements or precise metric units for laboratory work.
Everyday Use
Convert measurements for height, clothing sizes, furniture dimensions, and home improvement projects. Perfect for converting between metric and imperial measurements in daily life.
Sources & References
- National Institute of Standards and Technology (NIST) - Guide for the Use of the International System of UnitsOfficial conversion factors: 1 inch = 2.54 cm exactly, 1 meter = 3.28084 feet
- International System of Units (SI) - Base Unit DefinitionsOfficial definition: 1 meter = distance light travels in 1/299,792,458 seconds
- International Bureau of Weights and Measures (BIPM) - Metric System StandardsStandard metric length unit conversions and definitions
Need other conversion tools? Check out our area converter and feet to inches calculator.
Get Custom Calculator for Your PlatformLength Converter Examples
Input:
- Length: 5 meters
Conversion Steps:
- Start with 5 meters
- Convert to feet: 5 × 3.281 = 16.405 feet
- Convert to inches: 5 × 39.37 = 196.85 inches
- Convert to yards: 5 ÷ 0.9144 = 5.468 yards
- Convert to centimeters: 5 × 100 = 500 cm
Result: 5 meters = 16.405 feet = 196.85 inches
5 meters equals 16.405 feet, 196.85 inches, 5.468 yards, or 500 centimeters.
Input:
- Length: 10 kilometers
Conversion Steps:
- Start with 10 kilometers
- Convert to meters: 10 × 1,000 = 10,000 meters
- Convert to miles: 10 × 0.6214 = 6.214 miles
- Convert to feet: 10,000 × 3.281 = 32,810 feet
- Convert to nautical miles: 10,000 ÷ 1,852 = 5.4 nautical miles
Result: 10 kilometers = 6.214 miles
10 kilometers equals 6.214 miles, 10,000 meters, 32,810 feet, or 5.4 nautical miles.
12 Inches
12 × 2.54 =
30.48 cm
3 Feet
3 × 0.3048 =
0.9144 m
1 Mile
1 × 1.609 =
1.609 km
Frequently Asked Questions
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