Length Unit Converter
Precise length conversion for science, construction, travel, and everyday measurement
The Ultimate Length Unit Converter
Our length unit converter is a comprehensive tool that accurately transforms measurements between different length units including metric (millimeters, centimeters, meters, kilometers) and imperial (inches, feet, yards, miles) systems. This conversion is essential in science, construction, travel, and everyday measurements where different length systems are used.
Our precision converter handles all common length units with high accuracy, supporting decimal inputs and providing results to appropriate decimal places. It's particularly valuable for engineers, students, travelers, and anyone needing quick and accurate length conversions.
Input Length
Any length unit
Precise Conversion
Mathematical accuracy
Converted Result
Accurate length output
Length Converter
Conversion Formula
Quick Conversions
Complete Length Conversion Guide
Metric System Conversions
Millimeter (mm): 1 mm = 0.1 cm = 0.001 m
Centimeter (cm): 1 cm = 10 mm = 0.01 m
Meter (m): 1 m = 100 cm = 1000 mm
Kilometer (km): 1 km = 1000 m = 100,000 cm
The metric system is the international standard for scientific measurements and is used in most countries worldwide.
Imperial System Conversions
Inch (in): 1 in = 2.54 cm = 0.0833 ft
Foot (ft): 1 ft = 12 in = 0.3048 m
Yard (yd): 1 yd = 3 ft = 0.9144 m
Mile (mi): 1 mi = 5280 ft = 1.609 km
The imperial system is primarily used in the United States and some other countries for everyday measurements.
Common Length Conversions
1 meter = 3.28084 feet
1 foot = 0.3048 meters
1 inch = 2.54 centimeters
1 centimeter = 0.3937 inches
1 kilometer = 0.621371 miles
1 mile = 1.60934 kilometers
These are the most frequently used conversions in construction, engineering, and everyday applications.
Frequently Asked Questions
How do I convert meters to feet?
Multiply the number of meters by 3.28084 to get the equivalent in feet. For example, 5 meters = 5 × 3.28084 = 16.4042 feet.
What's the difference between metric and imperial units?
Metric units (mm, cm, m, km) use a decimal system based on powers of 10, while imperial units (in, ft, yd, mi) use various conversion factors. Metric is the international standard.
How accurate are these conversions?
Our conversions use exact mathematical relationships defined by international standards. For example, 1 inch is exactly 2.54 centimeters by definition.
Which units are most commonly used?
In construction: feet and meters. In engineering: millimeters and inches. In everyday use: centimeters and inches. For long distances: kilometers and miles.
How do I convert centimeters to inches?
Divide the number of centimeters by 2.54 to get inches. For example, 10 cm = 10 ÷ 2.54 = 3.937 inches.
What is the conversion factor for kilometers to miles?
Multiply kilometers by 0.621371 to get miles. For example, 5 km = 5 × 0.621371 = 3.10686 miles.
Conversion Tips & Best Practices
For Construction
- Use feet and inches for US projects
- Use meters and centimeters for international projects
- Always double-check critical measurements
For Engineering
- Use millimeters for precision work
- Specify tolerance requirements
- Document unit systems clearly
For Science
- Use metric units for all calculations
- Report significant figures appropriately
- Include uncertainty estimates
Conversion Formulas & Standards
Conversion Formulas
Multiply meters by 3.28084 to get feet.
Multiply feet by 0.3048 to get meters.
Based on international definition: 1 inch = 2.54 centimeters exactly.
International Standards
Official definition of the meter and its relationship to other length units.
BIPM SI Brochure →US standards for unit conversions and measurement precision.
NIST Measurements →Global standards for measurement and unit conversion.
ISO Standards →Conversion Methodology
Calculations use exact conversion factors based on international standards for maximum accuracy.
Results displayed to appropriate decimal places based on input precision and practical application needs.
Used in construction, engineering, scientific research, and international trade.
Conversion accuracy verified against multiple international standards and reference sources.