The inch equals 2.54 centimeters exactly since 1959. It is the global standard for screen diagonal sizes — a "55-inch TV" has a 139.7 cm diagonal. Pipe diameters, US and UK shoe sizes, and hard-drive form factors are all specified in inches. 1 inch = 1/12 foot = 1/36 yard.
Real-world: A 65-inch TV has a 165 cm diagonal. A smartphone screen is typically 6–7 inches. Standard copper plumbing in the UK is ½ inch or ¾ inch.
Read full inch reference →The statute mile equals 1609.344 meters exactly since the 1959 international definition. It is the official road unit in the United States, United Kingdom and Myanmar. The name comes from the Latin "mille passuum" — one thousand Roman paces. The nautical mile (1852 m) is different and used only in marine and air navigation.
Real-world: London to Edinburgh is about 400 miles by road. A marathon is 26.22 miles. US highways typically post 65–75 mph speed limits.
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