Length Converter
Convert between all common length units instantly with our free calculator. Convert meters to feet, cm to inches, mm to inches, feet to meters, and more. Supports both metric (mm, cm, m, km) and imperial (inches, feet, yards, miles) units. Key conversions: 1 inch = 2.54 cm | 1 foot = 0.3048 m | 1 meter = 3.28084 ft.
Quick Length Conversion Formulas
Master these key conversion factors to convert between metric and imperial length units:
Metric Units: 1 m = 100 cm = 1,000 mm | 1 km = 1,000 m
Imperial Units: 1 ft = 12 in | 1 yd = 3 ft | 1 mi = 5,280 ft = 1,760 yd
💡 Quick Values
💡 Common Metric Values
💡 Common Imperial Values
📋 Length Conversion Tables
Quick reference charts for converting between metric and imperial length units:
Metric to Imperial Conversion Chart
| Metric | Inches | Feet | Yards | Miles |
|---|---|---|---|---|
| 1 mm | 0.03937 | 0.00328 | 0.00109 | 6.21×10⁻⁷ |
| 1 cm | 0.3937 | 0.0328 | 0.0109 | 6.21×10⁻⁶ |
| 10 cm | 3.937 | 0.328 | 0.109 | 6.21×10⁻⁵ |
| 1 m | 39.37 | 3.281 | 1.094 | 0.000621 |
| 10 m | 393.7 | 32.81 | 10.94 | 0.00621 |
| 100 m | 3,937 | 328.1 | 109.4 | 0.0621 |
| 1 km | 39,370 | 3,281 | 1,094 | 0.621 |
| 10 km | 393,701 | 32,808 | 10,936 | 6.214 |
Imperial to Metric Conversion Chart
| Imperial | Millimeters | Centimeters | Meters | Kilometers |
|---|---|---|---|---|
| 1 inch | 25.4 | 2.54 | 0.0254 | 0.0000254 |
| 1 foot | 304.8 | 30.48 | 0.3048 | 0.000305 |
| 1 yard | 914.4 | 91.44 | 0.9144 | 0.000914 |
| 1 mile | 1,609,344 | 160,934 | 1,609.34 | 1.609 |
| 100 feet | 30,480 | 3,048 | 30.48 | 0.0305 |
| 100 yards | 91,440 | 9,144 | 91.44 | 0.0914 |
| 5,280 ft (1 mi) | 1,609,344 | 160,934 | 1,609.34 | 1.609 |
| 10 miles | 16,093,440 | 1,609,344 | 16,093 | 16.09 |
📐 Common Length Conversions
Height Conversions
- 5 feet = 152.4 cm = 1.524 m
- 5'6" = 167.64 cm = 1.68 m
- 6 feet = 182.88 cm = 1.83 m
- 170 cm = 5'7" = 66.93 in
- 180 cm = 5'11" = 70.87 in
Distance Conversions
- 1 km = 0.621 miles
- 5 km = 3.107 miles
- 10 km = 6.214 miles
- 1 mile = 1.609 km
- Marathon (26.2 mi) = 42.195 km
Small Measurements
- 1 inch = 25.4 mm = 2.54 cm
- 1 cm = 10 mm = 0.394 in
- 10 mm = 1 cm = 0.394 in
- 100 mm = 10 cm = 3.94 in
- 1 foot = 304.8 mm = 30.48 cm
Length Conversion Formulas & Key Facts
Master these essential formulas for converting between length units:
• Centimeters to Inches: inches = cm ÷ 2.54
• Meters to Feet: feet = m × 3.28084
• Kilometers to Miles: miles = km × 0.621371
Imperial to Metric:
• Inches to Centimeters: cm = inches × 2.54
• Feet to Meters: m = feet × 0.3048
• Miles to Kilometers: km = miles × 1.609344
Within Metric System:
• 1 km = 1,000 m = 100,000 cm = 1,000,000 mm
Within Imperial System:
• 1 mile = 1,760 yards = 5,280 feet = 63,360 inches
Key fact: 1 inch = 2.54 cm (exact by definition since 1959)
🔍 Frequently Asked Questions About Length Conversion
How many centimeters are in an inch?
1 inch equals exactly 2.54 centimeters. This is an exact conversion defined by international agreement in 1959. To convert inches to cm, multiply by 2.54. Example: 10 inches × 2.54 = 25.4 cm.
How many feet are in a meter?
1 meter equals 3.28084 feet. To convert meters to feet, multiply by 3.28084. Example: 2 meters × 3.28084 = 6.56168 feet. Conversely, 1 foot = 0.3048 meters.
How do I convert km to miles?
Multiply kilometers by 0.621371 to get miles. Example: 10 km × 0.621371 = 6.21 miles. Quick estimate: 8 km ≈ 5 miles.
What is 5 feet in centimeters?
5 feet equals 152.4 centimeters. Calculation: 5 × 30.48 = 152.4 cm. One foot = 30.48 cm exactly.
How many millimeters in an inch?
1 inch equals 25.4 millimeters. This is an exact conversion. To convert inches to mm, multiply by 25.4. Example: 3 inches × 25.4 = 76.2 mm.
What is the difference between metric and imperial?
The metric system (mm, cm, m, km) uses base-10 for easy conversions. The imperial system (in, ft, yd, mi) uses varying relationships: 12 in = 1 ft, 3 ft = 1 yd, 5,280 ft = 1 mi.
How many inches are in a foot?
1 foot equals 12 inches. To convert feet to inches, multiply by 12. Example: 5.5 feet × 12 = 66 inches.
How do I convert feet and inches to cm?
First convert feet to inches (feet × 12), add the inches, then multiply by 2.54. Example: 5'8" = (5×12)+8 = 68 inches × 2.54 = 172.72 cm.
How many yards in a mile?
1 mile equals 1,760 yards. A mile also equals 5,280 feet or 63,360 inches. In metric: 1 mile = 1.609344 kilometers.
What is 100 meters in feet?
100 meters equals 328.084 feet. Calculation: 100 × 3.28084 = 328.084 ft. This is slightly longer than a 100-yard (300 ft) football field.
How do I convert cm to inches?
Divide centimeters by 2.54 to get inches. Example: 50 cm ÷ 2.54 = 19.685 inches. For quick estimates: cm ÷ 2.5 gives approximate inches.
What countries use the imperial system?
Only the USA, Liberia, and Myanmar officially use the imperial system. The UK uses a mix of both systems. All other countries use the metric system as their primary measurement standard.
👥 Who Uses Length Converters?
Construction & Engineering
Convert architectural plans between metric and imperial measurements for building projects, structural calculations, and material ordering.
Woodworking & Carpentry
Convert lumber dimensions, cut lists, and project measurements between metric and imperial for furniture making and home improvement.
Sports & Fitness
Convert race distances, track lengths, and athletic measurements. Essential for runners, swimmers, and athletes tracking performance.
Travel & Navigation
Convert road distances, altitude readings, and travel distances between kilometers and miles for international trips and navigation.
Consumer Electronics
Convert screen sizes (measured in inches) to metric for TVs, monitors, tablets, and smartphones sold internationally.
Education & Science
Students and researchers use length converters for physics problems, lab measurements, and converting data between measurement systems.
❓ Length Conversion FAQ
In 1959, an international agreement standardized the inch as exactly 2.54 centimeters. This was adopted by the USA, UK, Canada, Australia, New Zealand, and South Africa to ensure consistent measurements across countries.
Use the 8:5 ratio for quick estimates: 8 km ≈ 5 miles. Or multiply km by 0.6 for a rough conversion. For precision, use km × 0.621371.
Step 1: Convert feet to inches (feet × 12). Step 2: Add any additional inches. Step 3: Multiply total inches by 2.54. Example: 5'10" = (5×12)+10 = 70 inches × 2.54 = 177.8 cm.
A statute mile (land mile) = 5,280 feet = 1.609 km. A nautical mile = 6,076 feet = 1.852 km. Nautical miles are used in aviation and maritime navigation.
Our calculator uses exact conversion factors defined by international standards. The inch-to-centimeter conversion (1 in = 2.54 cm) is exact by definition. Results are accurate to multiple decimal places.
The US officially uses US Customary Units (similar to imperial). The cost of switching infrastructure, signage, and education has made full metric adoption impractical, though metric is used in science, medicine, and the military.
1 yard = 0.9144 meters (exactly). This also equals 91.44 centimeters or 914.4 millimeters. A yard is equal to 3 feet or 36 inches.
An American football field is 100 yards = 91.44 meters (playing area only). Including end zones (10 yards each), the total is 120 yards = 109.73 meters. A soccer field varies from 100-110 meters in length.
This calculator uses exact conversion factors based on international standards. The meter is the SI base unit of length, defined by the speed of light. All conversions are mathematically precise to multiple decimal places.
Last reviewed and updated: February 15, 2026
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