Length Converter
inch to cm, cm to inch, meter, feet, miles – fast and precise
- Updated
You can type in either field.
Result in Inch (in)
0.3937008in
0.39370081 cm equals 0.3937008 in.
In all units
Tap a unit to make it the target.
Credit card, width (ISO/IEC 7810) is about 8.56 times your value.
- Your value0.3937008 in
- Credit card, width (ISO/IEC 7810)3.37 in
- A4 sheet, long side11.69 in
- Football pitch (105 m)4,134 in
- Zugspitze, height116,600 in
- Marathon1,661,000 in
- Earth’s circumference at the equator1,578,000,000 in
Bars on a logarithmic scale, values rounded.
How this was calculated
Both units are converted via the base unit m: 1 cm = 0.01 m and 1 in = 0.0254 m.
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Length units: overview and conversion factors
Metric system, imperial units and special measurements
The International System of Units (SI) defines the metre as the base unit of length. Since 1983, a metre has been defined via the speed of light: the distance light travels in a vacuum in 1/299,792,458 of a second. All metric units derive from powers of ten: 1 km = 1,000 m, 1 m = 100 cm = 1,000 mm. Before this exact definition, the metre was based on a platinum-iridium prototype bar kept in Sèvres near Paris. The redefinition via the speed of light makes the metre an unchanging physical constant.
The imperial system (US, UK) uses inches, feet, yards and miles. These units have historical roots in body measurements: the foot goes back to the average human foot length, and the inch originally meant "thumb width" and was based on the English king's thumb. Through international agreements, these units were fixed exactly to metric values: 1 inch = 2.54 cm (exact), 1 foot = 12 inches = 30.48 cm, 1 yard = 3 feet = 91.44 cm, 1 mile = 1,760 yards = 1,609.344 m. In everyday life you encounter imperial measurements with US products, screen diagonals and body height.
In maritime and aviation contexts, the nautical mile is the standard. It equals 1,852 m and derives from a geographic arcminute of the Earth's meridian. Speeds at sea are given in knots (kn) – 1 knot = 1 nautical mile per hour = 1.852 km/h. This uniform definition enables worldwide navigation without conversion issues on nautical charts and flight plans.
A common use case is height conversion: in the US and UK, height is given in feet and inches. 5 feet 10 inches (5'10") equals 5 × 30.48 + 10 × 2.54 = 152.4 + 25.4 = 177.8 cm. For screen and TV diagonals, the inch is the international standard measurement: a 65-inch TV has a diagonal of 65 × 2.54 = 165.1 cm. In construction, screws, pipes and tools are often sized in inches, even in Europe – a relic of the British origins of industrialization.
When converting, watch out for common sources of error: the statute mile (1,609.344 m, road traffic) and the nautical mile (1,852 m, seafaring) are different units. Likewise, the rod (roughly 3.7–4.7 m, historically variable by region) should not be confused with the yard (0.9144 m). Our converter works with the internationally valid, exactly defined values and provides results with sufficient precision for technical and everyday applications.
Common conversions in everyday life
The most important length conversions
- 1 inch = 2.54 cm
- Screen sizes, screws, height (US)
- 1 foot = 30.48 cm
- Height, room dimensions (US), altitude
- 1 mile = 1.609 km
- Road distances in the US and UK
- 1 yard = 91.44 cm
- Sports (golf, American football)
- 1 nautical mile = 1.852 km
- Maritime and aviation worldwide
- 1 km = 0.621 miles
- Conversion for US travel guides
Calculation examples
- Formula
- inch × 2.54 = cm
- Value
- 1 inch
- Factor
- 2.54
- Result
- 2.54 cm
- Formula
- cm ÷ 2.54 = inches
- Value
- 100 cm
- Divisor
- 2.54
- Result
- 39.37 inches
- Formula
- miles × 1.60934 = km
- Value
- 60 miles
- Factor
- 1.60934
- Result
- 96.56 km
- Formula
- feet × 0.3048 = meters
- Value
- 6 feet
- Factor
- 0.3048
- Result
- 1.829 m
Frequently asked questions about the length converter
Everything about centimeters, inches, meters, feet and miles
How many centimeters are in an inch?
One inch (symbol: in) equals exactly 2.54 centimeters. This is an internationally fixed definition. Conversely, 1 cm = 0.3937 inches.
How do I convert miles to kilometers?
One statute mile equals exactly 1.609344 kilometers. To convert miles to kilometers, multiply the number of miles by 1.6093. Example: 60 miles = 60 × 1.6093 = 96.56 km.
What is the difference between a foot and a yard?
1 foot (ft) = 30.48 cm. 1 yard (yd) = 3 feet = 91.44 cm. Feet are commonly used for height (in English-speaking countries) and altitude (e.g. flight altitude in aviation). Yards are a common unit in sports (e.g. American football, golf).
What is a nautical mile?
One nautical mile (nmi) = 1,852 meters. The nautical mile is the standard unit in maritime and aviation navigation and corresponds to one arcminute on the Earth's meridian. Speed in nautical miles per hour is called a knot.
How tall is 5 feet 11 inches in meters?
5 feet 11 inches equals 5 × 30.48 cm + 11 × 2.54 cm = 152.4 cm + 27.94 cm = 180.34 cm, or roughly 1.80 m. Our calculator converts feet and inches separately – simplest is to convert both values separately and add the results.