Length Converter
Free length converter for mm, cm, meters, km, inches, feet, yards, and miles. Instant results with conversion tables and real-world examples.
A length converter handles any measurement unit instantly, from millimeters to miles. Whether you need to convert clothing sizes or check road distances, this length converter handles any unit instantly. Supported units: millimeters (mm), centimeters (cm), meters (m), kilometers (km), inches (in), feet (ft), yards (yd), and miles (mi). According to the National Institute of Standards and Technology (NIST), the meter is the SI base unit of length. All metric units derive from it through powers of ten.
Imperial units are used primarily in the United States. They follow fixed conversion factors: 12 inches per foot, 3 feet per yard, and 5,280 feet per mile. Every conversion formula on this page follows exact internationally standardized values.
How to Use This Length Converter
Enter any value in the input field above, select the source unit from the left dropdown, and choose the target unit from the right. Results update instantly. The converter supports all combinations across metric and imperial units, including millimeters, centimeters, meters, kilometers, inches, feet, yards, and miles. For the most common conversion pairs, use the dedicated sections below for formulas, reference tables, and named real-world examples.
Centimeters to Inches
The centimeters to inches conversion is the most-searched length conversion globally. One inch equals exactly 2.54 centimeters, a standard set under the International Yard and Pound Agreement of 1959. To convert centimeters to inches, divide the centimeter value by 2.54, or multiply by 0.3937. This conversion is used for clothing sizes, TV and monitor screen sizes, furniture dimensions, and international product specifications.
Formula: inches = cm ÷ 2.54
| Centimeters (cm) | Inches (in) |
|---|---|
| 1 cm | 0.394 in |
| 5 cm | 1.969 in |
| 10 cm | 3.937 in |
| 15 cm | 5.906 in |
| 20 cm | 7.874 in |
| 25 cm | 9.843 in |
| 30 cm | 11.811 in |
| 50 cm | 19.685 in |
| 100 cm | 39.370 in |
| 150 cm | 59.055 in |
| 180 cm | 70.866 in |
| 200 cm | 78.740 in |
Real-world references: A standard A4 sheet is 29.7 cm long (11.69 inches). A typical adult height of 180 cm equals 70.87 inches, or 5 feet 10.87 inches. A 65-inch TV screen measures 165.1 cm diagonally. A standard ruler is 30 cm (11.81 inches).
For a dedicated page with extended values, use DigiCalc's cm to inches converter.
Millimeters to Inches
The mm to inches conversion is essential in engineering, manufacturing, woodworking, and 3D printing, where specifications frequently cross metric and imperial systems. One inch equals exactly 25.4 millimeters. The millimeters to inches formula gives either a decimal result or a fractional result depending on the application. For the mm to inches conversion in fractional format, divide mm by 25.4 first. Then express the decimal as the nearest standard fraction (1/8, 1/4, 3/8, 1/2, etc.). This is the standard mm to inches fraction method used in machining tolerances and carpentry. Use this mm to inches chart below as a quick reference for common values.
Formula: inches = mm ÷ 25.4
| Millimeters (mm) | Decimal Inches | Fraction (approx.) |
|---|---|---|
| 1 mm | 0.0394 in | 3/64 in |
| 2 mm | 0.0787 in | 5/64 in |
| 3 mm | 0.1181 in | 7/64 in |
| 5 mm | 0.1969 in | 13/64 in |
| 10 mm | 0.3937 in | 25/64 in |
| 12.7 mm | 0.500 in | 1/2 in |
| 19.05 mm | 0.750 in | 3/4 in |
| 25.4 mm | 1.000 in | 1 in |
| 50 mm | 1.969 in | 1 63/64 in |
| 100 mm | 3.937 in | 3 15/16 in |
| 150 mm | 5.906 in | 5 29/32 in |
| 200 mm | 7.874 in | 7 7/8 in |
Real-world references: A standard credit card is 85.6 mm long (3.37 inches). A US quarter coin is 24.26 mm in diameter (0.955 inches). A standard M6 bolt diameter is 6 mm (0.236 inches).
For a dedicated reference, see DigiCalc's mm to inches converter.
Kilometers to Miles
The kilometers to miles conversion is the primary length conversion for international travel, athletics, navigation, and vehicle speed. One kilometer equals exactly 0.621371 miles. To convert km to miles, multiply the kilometer value by 0.621371. For a miles to kilometers converter (reverse direction), multiply the mile value by 1.60934.
Formulas:
- Miles = km × 0.621371
- Kilometers = miles × 1.60934
| Kilometers (km) | Miles |
|---|---|
| 1 km | 0.621 mi |
| 3 km | 1.864 mi |
| 5 km | 3.107 mi |
| 10 km | 6.214 mi |
| 21.1 km | 13.109 mi (half marathon) |
| 42.195 km | 26.219 mi (full marathon) |
| 50 km | 31.069 mi |
| 100 km | 62.137 mi |
| 500 km | 310.686 mi |
| 1,000 km | 621.371 mi |
Real-world references: London to Paris is approximately 341 km (212 miles) straight-line distance. A standard 5K race is 5 km (3.107 miles). The circumference of Earth at the equator is 40,075 km (24,901 miles).
Meters to Feet
The meters to feet conversion is critical in construction, architecture, aviation, and sports. To convert meters to feet, multiply the meter value by 3.28084. For meters to yards, multiply by 1.09361. To convert to feet and inches together, multiply meters by 3.28084 and take the whole number as feet. Then multiply the remaining decimal by 12 to get inches.
Formulas:
- Feet = meters × 3.28084
- Yards = meters × 1.09361
| Meters (m) | Feet (ft) | Feet and Inches | Yards (yd) |
|---|---|---|---|
| 1 m | 3.281 ft | 3 ft 3.37 in | 1.094 yd |
| 1.5 m | 4.921 ft | 4 ft 11.05 in | 1.640 yd |
| 1.8 m | 5.906 ft | 5 ft 10.87 in | 1.969 yd |
| 2 m | 6.562 ft | 6 ft 6.74 in | 2.187 yd |
| 5 m | 16.404 ft | 16 ft 4.85 in | 5.468 yd |
| 10 m | 32.808 ft | 32 ft 9.70 in | 10.936 yd |
| 50 m | 164.042 ft | 164 ft 0.50 in | 54.681 yd |
| 100 m | 328.084 ft | 328 ft 1.01 in | 109.361 yd |
Real-world references: The Eiffel Tower stands 330 m tall (1,082.7 ft). A standard Olympic swimming pool is 50 m long (164 ft or 54.7 yd). The average ceiling height in a residential room is 2.4 m (7.87 ft).
Feet to Meters
To convert feet to meters, multiply the foot value by 0.3048. This exact conversion factor has been internationally standardized since the 1959 International Yard and Pound Agreement. The reverse is equally useful when filling out international paperwork or comparing building heights across countries. It also applies when converting a personal height from US format (feet and inches) to the metric format used elsewhere.
Formula: meters = feet × 0.3048
Quick reference: how many inches in a foot? There are exactly 12 inches in one foot. There are 3 feet in one yard, and 5,280 feet in one mile.
| Feet (ft) | Meters (m) |
|---|---|
| 1 ft | 0.305 m |
| 2 ft | 0.610 m |
| 3 ft | 0.914 m |
| 5 ft | 1.524 m |
| 5 ft 6 in | 1.676 m |
| 5 ft 9 in | 1.753 m |
| 6 ft | 1.829 m |
| 10 ft | 3.048 m |
| 100 ft | 30.480 m |
For entering heights in feet and inches together (for example, 5 feet 9 inches to cm), see DigiCalc's cm to feet converter.
32 Inches in cm
32 inches in cm equals 81.28 centimeters. Multiply 32 by 2.54 to get the result: 32 x 2.54 = 81.28 cm. This conversion is commonly searched for TV and monitor screen sizes. Screen diagonals are measured in inches, but product listings outside the US show centimeters. A 32-inch display measures 81.28 cm diagonally.
65 Inches in cm
65 inches in cm equals 165.10 centimeters. Using the formula: 65 x 2.54 = 165.1 cm. A 65-inch TV screen measures 165.1 cm diagonally, making it one of the most popular large-screen sizes worldwide. In height terms, 65 inches equals 5 feet 5 inches, or approximately 1.651 meters.
50 Inches in cm
50 inches in cm equals 127 centimeters. The calculation: 50 x 2.54 = 127 cm exactly. A 50-inch TV screen measures 127 cm diagonally. In height, 50 inches equals 4 feet 2 inches (1.27 meters). The value 127 cm is also the standard carry-on luggage size limit used by many international airlines.
Convert Metric to Inches: Quick Reference Charts
The tables below serve as quick reference charts for converting metric to inches. The cm to inches chart covers clothing sizes, screen dimensions, and everyday measurements. The mm to inches chart covers hardware, fasteners, and precision parts. Use the cm to inches converter above for values not listed here.
| Centimeters (cm) | Inches | Millimeters (mm) | Inches |
|---|---|---|---|
| 1 cm | 0.394 in | 10 mm | 0.394 in |
| 5 cm | 1.969 in | 25 mm | 0.984 in |
| 10 cm | 3.937 in | 50 mm | 1.969 in |
| 20 cm | 7.874 in | 75 mm | 2.953 in |
| 30 cm | 11.811 in | 100 mm | 3.937 in |
| 50 cm | 19.685 in | 150 mm | 5.906 in |
| 100 cm | 39.370 in | 200 mm | 7.874 in |
The Metric System and Imperial Units: Key Differences
The metric system uses the meter as its foundation, defined since 1983 as the distance light travels in vacuum in exactly 1/299,792,458 of a second. Every metric unit follows a base-10 structure: 1 meter equals 10 decimeters, 100 centimeters, 1,000 millimeters, or 0.001 kilometers. This decimal structure makes unit conversion within the metric system a simple matter of multiplying or dividing by powers of ten.
The imperial units used in the United States follow historically derived, non-decimal relationships. These include: 12 inches per foot, 3 feet per yard, and 5,280 feet per mile. These ratios derive from Roman and Anglo-Saxon measurement units standardized in the 13th century. The imperial system is the primary system for everyday use only in the United States. The United Kingdom uses a hybrid: miles for road distances, but meters and centimeters in most other official contexts. All other countries use the metric system exclusively.
| Metric Unit | SI Units Definition | Imperial Equivalent |
|---|---|---|
| Millimeter (mm) | 0.001 m | 0.03937 in |
| Centimeter (cm) | 0.01 m | 0.3937 in |
| Decimeter (dm) | 0.1 m | 3.937 in |
| Meter (m) | Base unit | 3.28084 ft |
| Kilometer (km) | 1,000 m | 0.621371 mi |
| Imperial Unit | Definition | Metric Equivalent |
|---|---|---|
| Inch (in) | 1/12 foot | 25.4 mm |
| Foot (ft) | 12 inches | 0.3048 m |
| Yard (yd) | 3 feet | 0.9144 m |
| Mile (mi) | 5,280 feet | 1.60934 km |
Complete Length Conversion Formula Reference
The table below consolidates every common length unit conversion into a single reference. All factors follow exact internationally defined values from NIST and BIPM.
| Convert From | Convert To | Multiply By |
|---|---|---|
| Inches | Centimeters | 2.54 |
| Centimeters | Inches | 0.3937 |
| Inches | Millimeters | 25.4 |
| Millimeters | Inches | 0.03937 |
| Feet | Meters | 0.3048 |
| Meters | Feet | 3.28084 |
| Yards | Meters | 0.9144 |
| Meters | Yards | 1.09361 |
| Miles | Kilometers | 1.60934 |
| Kilometers | Miles | 0.621371 |
| Feet | Centimeters | 30.48 |
| Centimeters | Feet | 0.032808 |
| Inches | Feet | 0.08333 |
| Feet | Inches | 12 |
| Yards | Feet | 3 |
Real-World Length Measurement References
Named references help build intuition for common unit sizes:
- Human hair width: approximately 70 micrometers (0.07 mm, 0.003 in)
- Standard credit card: 85.6 mm x 54 mm (3.37 in x 2.13 in)
- Standard A4 paper: 297 mm x 210 mm (11.69 in x 8.27 in)
- Standard interior door height in the US: 6 ft 8 in (203.2 cm, 2,032 mm)
- Average adult stride length: approximately 75 cm (29.5 in, 2.46 ft)
- NBA basketball court length: 28.65 m (94 ft, 31.33 yd)
- Boeing 747 wingspan: 68.4 m (224.4 ft, 74.8 yd)
- Burj Khalifa height: 828 m (2,716.5 ft, 0.514 miles)
- Mount Everest summit: 8,848.86 m (29,031.7 ft, 5.498 miles)
- Amazon River length: approximately 6,400 km (3,977 miles)
Limitations of This Length Converter
This tool converts between standard everyday and professional length units. It does not convert units in specialized scientific or surveying contexts: astronomical units (AU), light-years, parsecs, angstroms, or nautical miles. It also excludes US survey feet, which differ from international feet by approximately 2 parts per million and are used in US land surveying. For scientific or land surveying applications, use domain-specific reference tools. Results display rounded to 4 to 6 significant figures. For manufacturing tolerances or precision calibration, verify values against official NIST or BIPM reference tables and apply the rounding appropriate to the specific application.
All Length Converters on DigiCalc
DigiCalc provides individual converters for every common length unit pair. Select any converter below for a dedicated reference with formulas, charts, and examples:
- Centimeters to Meters (cm to m)
- Centimeters to Millimeters (cm to mm)
- Centimeters to Decimeters
- Millimeters to Meters (mm to m)
- Inches to Meters
- Feet to Meters
- Feet to Inches
- Feet to Yards
- Feet and Inches Calculator
- Kilometers to Feet
- Kilometers to Miles
- Miles to Kilometers
- Feet to Miles
- Meters to Miles
- Yards to Meters
- Yards to Centimeters
- Yards to Inches
- Yards to Miles
- Pixels to Inches
- Kiloparsec to Meters (astronomical distance)
- Petameter to Meters (astronomical distance)
For mass unit conversions, see DigiCalc's weight converter (kg, lbs, grams, ounces, stones). For temperature, use the temperature converter (Celsius, Fahrenheit, Kelvin).