Converting from Inches to Centimeters
2.54 does the whole job: multiply by it. It's exact, not rounded, so 100 inches is exactly 254 cm and a 12 inch ruler is 30.48 cm.
Fractions are the awkward part. Turn them into decimals first – 5 3/4 inches is 5.75 inches, which makes 14.605 cm – and round at the end rather than halfway through.
Screen sizes are a good test: a 55 inch TV measures 139.7 cm corner to corner, which is the figure hiding in the small print on the box.
About Centimeters
The Centimeter is a unit in the metric system, which is used everywhere around the world apart from the United States and Burma.
Centimeters are smaller than inches. There are 2.54 centimeters in an inch. Centimeters are often used for smaller measurements in science, engineering and construction. They are also used in situations like measuring the length of objects or clothing.
The big advantage of using centimeters rather than imperial units is that they are based on powers of ten.
What are inches?
Inches are commonly used in the United States and the United Kingdom. An inch is defined as one twelth (1/12th) of a foot and used to measure small distances like the length of a pencil or the width of a book.
Inches are often used in construction, carpentry and engineering. They are also often found in the fashion industry for determining clothing sizes and are used to specify screen sizes for TVs and computer monitors.
To convert inches to other units you need to know the appropriate conversion factor. For example, to convert inches to centimeters you need to multiply the inch value by 2.54. To convert inches to millimeters the inch measurement is multiplied by 25.4.
Inches are used mainly in the United States but it is common to find people using inches in the United Kingdom especially for body measurements, trades and fashion. Inches are a standard worldwide in electronics and semiconductors.
Which countries use inches?
The United States is the most notable country that uses inches but a large number of people still use them in the United Kingdom as well. In the US, inches are the standard in construction and engineering. Inches are also common in determining a person's height or the size of television screens.
Although the UK has officially adopted the metric system, inches are still found in certain area particularly in construction. This is due to the historical influence of the imperial system. In the UK inches are also used for body height and objects that were traditionally measured this way such as vinyl records.
Which countries use centimeters?
A majority of countries worldwide have adopted the metric system and as such use centimeters.
In these countries millimeters are the preferred unit for measuring dimensions of building materials, such as pipes, beams, and panels. Centimeters are found in manufacturing, machinery and tools. Centimeters are also used in medicine and are used in the fashion and textile industry.