1 Inch to Millimeters – How to Convert?

This post was last updated on January 20th, 2023 at 12:26 pm

How Many Millimeters Are In 1 Inch? 1 inch is equal to 25.4 millimeters (mm). By definition, an inch is equal to 2.54 centimeters (cm). A millimeter is the tenth part of a centimeter. Therefore, to get a value of one millimeter, a centimeter has to be divided by ten. Converting from millimeters to inches would equal 2.54 divided by 10. The value returns 25.4 mm.

A look at history would provide a better understanding of the inch definition. The metrics of inches date as far back as the 1100s when king David I defined the imperial unit of an inch as the breadth of a man’s thumb. These metrics stayed for over three hundred years until king Edward II adjusted the customary units. The value of an inch introduced by King Edward was the length of three dried round grains of barley placed side by side.

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it was in 1959 that the international community finally set the value of an inch under the standard unit of measurement or systems of measurement at 2.5 centimeters (cm). This metric is what we’ve used to this day. Knowing the standard value makes it easy for anyone to convert from inch to any other system of measurement. However, there are different equivalents of inches in other metric systems. For example, the value of an inch in yards is 1/36 or 0.028 yards.

This article answers questions bothering around the conversion of millimeters into inches and explains how to apply simple arithmetic to take a measurement from inches to millimeters. 

Jump right into the Frequently Asked Questions

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How Many Millimeters Are In 1 Inch Table of Contents

Millimeters to Inches

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Millimeter (mm)Inches (in)
1 mm0.039 in
2 mm0.079 in
3 mm0.118 in
4 mm0.157 in
5 mm0.197 in
6 mm0.236 in
7 mm0.276 in
8 mm0.315 in
9 mm0.354 in
10 mm0.394 in
20 mm0.787 in
30 mm1.181 in
40 mm1.575 in
50 mm1.969 in
60 mm2.362 in
70 mm2.756 in
80 mm3.150 in
90 mm3.543 in
100 mm3.937 in
200 mm7.874 in
300 mm11.811 in
400 mm15.748 in
500 mm19.685 in
600 mm23.622 in
700 mm27.559 in
800 mm31.496 in
900 mm35.433 in
1000 mm39.370 in

Inches to Millimeter

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Inches (in)Millimeter (mm)
1 in25.4 mm
2 in25.4 mm
3 in76.2 mm
4 in101.6 mm
5 in127.0 mm
6 in152.4 mm
7 in177.8 mm
8 in203.2 mm
9 in228.6 mm
10 in254 mm
20 in508 mm
30 in762 mm
40 in1016 mm
50 in1270 mm
60 in1524 mm
70 in1778 mm
80 in2032 mm
90 in2286 mm
100 in2540 mm
200 in5080 mm
300 in7620 mm
400 in10160 mm
500 in12700 mm
600 in15240 mm
700 in17780 mm
800 in20320 mm
900 in22860 mm
1000 in25400 mm

Learn more about how many millimeters are in 1 inch (video)

Convert Milimeter to Inch (mm to in) – Formula, Example, Convertion Factor by How Convert

Frequently Asked Questions

How many mm means 1 inch?

1 inch equals 25.4 mm. Since the value of one inch is 2.54 centimeters. Multiply 2.54 by 10 to get the value of 1 inch in mm.

Is 1 inch the same as 5mm?

No. One inch is 25 times larger than the values of millimeters. Therefore, to get the inches equivalent of any millimeter value, you’ll divide by 25.4 because 1 inch is equal to 25.4 mm. 5mm is equal to 0.19685.

Is an inch exactly 25.4 mm?

Yes. The exact value of an inch is 25.4, which is ten times the equivalent of inches to centimeters (2.54 cm)

What size are 2 inches in mm?

2 inches in millimeters is 50.8. Multiply 2 by 25.4 and the value returns 50.8

How do you convert inches to millimeters?

There are several ways to carry out millimeter-to-inch conversions. The first and obvious method is to use digital inch converters present on mobile devices or other gadgets to change your values from inch to millimeters or any other powerful calculator tools. The second method is to use an online conversion calculator available on web platforms or web apps.

Finally, you can use simple arithmetic to convert your value in inches into millimeters, following established mathematical formulas. To perform the arithmetic, you need your conversion factor, which is 25.4 mm. The conversion factor is dictated by the standard unit of measurement as the value of a unit of an inch in millimeters.

The next step is to multiply the value of inches by the conversion factor. It would give you the inches equivalent of any millimeter value. For example, 10 inches would equal 254 millimeters (mm)

Is mm bigger or cm bigger?

No. Centimeter is bigger than millimeter. The millimeter is ten parts of a centimeter. I.e, you’ll divide one centimeter into ten parts to get the value of one millimeter. 1mm equals 1/10 cm or 0.1 cm. Milli- by standard equals 1/1000 or 0.001. And centi- equals 1/100 or 0.01.

How big is a millimeter’s actual size?

One millimeter is almost as big as the thickness of two human nails (grown adult). It Is the length of the space between two strokes of line on any ruler or tape rule calibrated in centimeters.

It’s difficult to take any measurement in millimeters without the aid of measuring equipment, due to the smallness of millimeters. Again, the length of the index finger of an adult is anywhere from 50 millimeters (mm) to 100+ millimeters (mm)

What is an example of a millimeter?

There are several everyday items that have approximately millimeters in size. The thickness of the human fingernail thumb) is almost half a millimeter. The thickness of two id cards is about 1.4 mm in size: given that a single id card measures 0.03 inches.

The thickness of 10 sheets of paper is 1 mm since a single sheet of paper is 0.1 mm in size. Sim cards are also 1 mm thick. Memory cards too are 1 mm thick.

How thick is 9 mm in inches?

9mm is equal to 0.354331 inches or approximately 0.35 inches.


Converting from one metric unit to another is critical in most fields of life. Going from measurements such as Millimeters to inches is an essential practice in human interaction. Inches, yards, and feet are some of the most common units of measurement used in the United States, the UK, and some other parts of the world. And each of these units is denoted by standard symbols.

Other popular units include meters, centimeters, millimeters, and kilometers. These measurements had the customary systems used to denote them in the past before the introduction of standardized measurement.

Some examples include the use of the human thumb, seeds, grains, etc. This article has given a brief review of the measurement of inches in millimeters. If you have any questions or need further clarification, leave them in the comment section and remember to share the article.

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