The United States make use of the empirical measurement system that include the inches but the remaining world uses the metric system.  In some particular times, there is a need to convert a measurement from the inches to the millimeters in order to have a better understanding.  When there is knowledge of proper equation, converting becomes pretty simple.  There are few processes of this conversion.

1. One inch is accepted to be equivalent to 25. 4 millimeters.  It is written as the equations and this relationship presents itself as 1 in = 25. 4 mm.  This is an official and standardized measurement which has been set in terms of the international records since the year 1959.  Both the inches and the millimeters are considered to be the measurement units.  In the English system of measurement, inches are belonged and at the same time, millimeters are connected with the metric system of measurement. In the United States, inches are used and in Canada, this unit of measurement needs to be converted to one belonging in the metric system.
2. In order to convert a measurement that is taken in inches, the problem needs to begun having written down the original measurement.  The measurement will be converted into the millimeters having compared it to the connection between millimeters and inches.
3. After this, one needs to multiply the current inch measurement through the ratio of the millimeters to inches such as 25.4 mm /1 in. The value of the inches needs to be placed in the dominator as it will have to cancel the inches value in the original measurement. After all the inches cancel out, the milometers stays as the only remaining unit of the measurement.  Take n for example- 7 in ( 25.4 mm / 1 in)= 177.8 mm (in/in)= 177.8 mm

 There are other methods too. Those are as follows-

A ruler can be used. A ruler is 12 inches long and in most of the rulers the inches are given on one side but also the centimeters are listed along with the millimeters on the other side. When the original measurement is 12 inch or below, one of those rulers can be used for measuring the same distance in the millimeters. It also has to be noted that millimeter marks are the small dashes between the large centimeter measurements. It should be 10 mm per 1 cm. As another alternative, websites can be used to convert the measurement automatically. When it is needed to find out the millimeter that is equivalent to a measurement in the inches, it can be done through using the automatic website for conversion.  Firstly, the website need to be opened and the conversion boxes should be located.  The numbers need to be typed into the respective boxes and the units need to be selected when necessary. The calculate button is always there which corresponds with showing the answer. This third process is looking at the common conversion chart.  One might be able to locate the measurement on a conversion chart for smaller amounts or inches. It is equivalent to the chart that has been given below. The number of inches can be located to view the number of millimeters equal to the inch value.

• 1/64 in = 0.3969 mm
• 1/32 in = 0.7938 mm
• 1/16 in = 1.5875 mm
• 1/8 in = 3.1750 mm
• 1/4 in = 6.3500 mm
• 1/2 in = 12.7000 mm
• 3/4 in = 19.0500 mm
• 7/8 in = 22.2250 mm
• 15/16 in = 23.8125 mm
• 31/32 in = 24.6062 mm
• 63/64 in = 25.0031 mm
• 1 in = 25.4001 mm
• 1 1/8 in = 28.5750 mm
• 1 1/4 in = 31.7500 mm
• 1 3/8 in = 34.9250 mm
• 1 1/2 in = 38.1000 mm
• 1 5/8 in = 41.2750 mm
• 1 3/4 in = 44.4500 mm
• 2 in = 50.8000 mm
• 2 1/4 in = 57.1500 mm
• 2 1/2 in = 63.5000 mm
• 2 3/4 in = 69.8500 mm
• 3 in = 76.2000 mm
• 3 1/4 in = 82.5500 mm
• 3 1/2 in = 88.9000 mm
• 3 3/4 in = 95.2500 mm
• 4 in = 101.6000 mm
• 4 1/2 in = 114.3000 mm
• 5 = 127.0000 mm
• 5 1/2 in = 139.7000 mm
• 6 in = 152.4000 mm
• 8 in = 203.2000 mm
• 10 in = 254.0000 mm