Inches to millimeters

Change from inches to millimeters easily thanks to our online converter that allows you to obtain the equivalence between both units instantly and without calculations.

How many millimeters is an inch?

Inches is a unit of length with which we are not familiar since it does not belong to the International System of Units. Therefore, if you are asked how many millimeters is an inch you probably don't know it but we give you the answer below:

1 inch = 25.4 millimeters

¿Y how many inches is 1 millimeter? Let's take a look at it:

1 millimeter = 0.0393701 inches

Now that we know the equivalence between inches and millimetersIn this section, let's see how to go from one unit to another, with the formula and using Excel.

How to convert inches to mm

Now that you know how many millimeters are in an inch, it's easy to draw a formula to convert from inches to mm. To save you the trouble, we put it below:

mm = inches x 25.4

For example, do youhow many mm is 2 inches? We apply the above formula and we have the result:

2 inches x 25.4 = 50.8 millimeters

The conversion is very simple so you will only need a calculator to do the multiplication or use our inch to mm converter.

Conversion from millimeters to inches

See how to convert millimeters to inches. In this case, the formula to be used will be the following:

inches = mm x 0.0393701

Another formula to convert millimeters to inches is this:

inches = mm / 25.4

Applied to a practical example, we are going to calculate how many inches is 100 mm:

100 x 0.0393701 = 3.93701 millimeters

100 / 25.4 = 3.93701 mm

As you can see, in both cases we obtain the same result so that you can use either of the two formulas. Perhaps it is easier to remember to divide by 25.4 because it is a smaller number and does not have so many decimal places.


Convert inches to millimeters in Excel

Inches to mm in Excel

Do you want to make your own inch to mm converter? You only need to have Excel installed on your computer to make one, so you can make the conversion whenever you need it and without calculations.

If you have Excel, open a new spreadsheet and type in a cell the following function:


Para que funcione, sólo tienes que sustituir "C1" por las coordenadas de la celda en la que hayas escrito la cantidad de inches you want to convert to millimeters. You can also write the length in inches directly there.

For example, if we want to calculate how many mm is 3 inchesthe function must be written like this:


After pressing the Enter key on your keyboard, the result will appear automatically.

Converting from mm to inches in Excel

mm to inches in Excel

In the same way as in the previous case, we can also do a mm to inch converter with Excel. The method is the same only that we will invert the order of the conversion so the formula to use will be the following:


¿How many inches is 50 mm? Let's calculate it with Excel and what we have just learned:


Accept the operation and Excel will return that in 50 millimeters there are 1,968 inches.

Table of equivalence inches to mm

Inch to millimeter converter

Below you have a table with some of them equivalences from inches to millimeters. If you usually work with these two units of length, you can print this table and always carry it with you to make conversions without using our tool.


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