What is an inch and a half in metric

Please provide values below to convert inch [in] to millimeter [mm], or vice versa.

Inch

Definition: An inch (symbol: in) is a unit of length in the imperial and US customary systems of measurement. An inch was defined to be equivalent to exactly 25.4 millimeters in 1959. There are 12 inches in a foot and 36 inches in a yard.

History/origin: The term "inch" was derived from the Latin unit "uncia" which equated to "one-twelfth" of a Roman foot.

There have been a number of different standards for the inch in the past, with the current definition being based on the international yard. One of the earliest definitions of the inch was based on barleycorns, where an inch was equal to the length of three grains of dry, round barley placed end-to-end. Another version of the inch is also believed to have been derived from the width of a human thumb, where the length was obtained from averaging the width of three thumbs: a small, a medium, and a large one.

Current use: The inch is mostly used in the United States, Canada, and the United Kingdom. It is also sometimes used in Japan (as well as other countries) in relation to electronic parts, like the size of display screens.

Millimeter

Definition: A millimeter (symbol: mm) is a unit of length in the International System of Units (SI). It is defined in terms of the meter, as 1/1000 of a meter, or the distance traveled by light in 1/299 792 458 000 of a second.

History/origin: The milli- prefix is one of many metric prefixes. It indicates one thousandth of the base unit, in this case the meter. The definition of the meter has changed over time, the current definition being based on the distance traveled by the speed of light in a given amount of time. The relationship between the meter and the millimeter is constant however. Prior to this definition, the meter was based on the length of a prototype meter bar. In 2019, the meter has been re-defined based on the changes made to the definition of a second.

Inch to Millimeter Conversion Table

How to Convert Inch to Millimeter

1 in = 25.4 mm
1 mm = 0.0393700787 in

Example: convert 15 in to mm:
15 in = 15 × 25.4 mm = 381 mm

Popular Length Unit Conversions

Convert Inch to Other Length Units

To convert inches to millimeters (in to mm), you may use the inches to mm converter above. Alternatively, to find out how many millimeters there are in "x" inches, you may use the inches to mm table.

Below, you will find information of how to find out how many mm there are in "x" inches, including the formulas and example conversions.

How many millimeters (mm) in an inch?

There are 25.4 millimeters in an inch. To convert inches to millimeters, multiply the inch value by 25.4.

For example, to find out how many millimeters there are in a half inch, multiply 0.5 by 25.4, that makes 12.7 mm in a half inch.

inches to mm formula

mm = inch * 25.4

How to convert millimeters to inches?

1 Millimeter (mm) is equal to 0.0393700787 inch (in). To convert millimeters to inches, multiply the millimeter value by 0.0393700787 or divide by 25.4.

For example, to convert 50 mm to inches, divide 50 by 25.4, that makes 1.9685 inch in 50 mm.

mm to inches formula

inch = mm * 0.0393700787

inch = mm / 25.4

What is an Inch?

Inch is an imperial and United States Customary systems unit of length. 1 inch = 25.4 mm. The symbol is "in".

What is a Millimeter?

Millimeter (millimetre) is a metric system unit of length. 1 mm = 0.0393700787 inch. The symbol is "mm".

Please visit all length units conversion to convert all length units.

Create Conversion Table

Click "Create Table". Enter a "Start" value (5, 100 etc). Select an "Increment" value (0.01, 5 etc) and select "Accuracy" to round the result.

Half inch equals 12.7 millimeters because half times 25.4 (the conversion factor) = 12.7

All In One Unit Converter

Definition of Inch

An inch is a unit of length or distance in a number of systems of measurement, including in the US Customary Units and British Imperial Units. One inch is defined as 1⁄12 of a foot and is therefore 1⁄36 of a yard. According to the modern definition, one inch is equal to 25.4 mm exactly.

Definition of Millimeter

A millimeter (mm) (mispeled millimeter) is a decimal fraction of the meter, the International System of Units (SI) unit of length, approximately equivalent to 39.37 inches.

How to convert 0.5 inch to millimeters

To calculate a value in inches to the corresponding value in millimeters, just multiply the quantity in inches by 25.4 (the conversion factor).

Here is the formula:

Value in millimeters = value in inches × 25.4

Supose you want to convert half inch into millimeters. In this case you will have:

Value in millimeters = 0.5 × 25.4 = 12.7

Inches to Millimeters Conversion Chart

Note: Fractions are rounded to the nearest 8th fraction. Values are rounded to 4 significant figures.

Using this converter you can get answers to questions like:

• How many millimeters are there in half inch?
• Half inch is equal to how many millimeters?
• How much is half inch in millimeters?
• How to convert inches to millimeters?
• What is the inches to millimeters conversion factor?
• How to transform inches in millimeters?
• What is the formula to convert from inches to millimeters? among others.

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