How many millimeters in an inch

How many millimeters in an inch

Inches to Millimeters Conversion Calculator

Enter the length in inches below to get the value converted to millimeters.


 Inch Fraction Numerator:

Results in Millimeters:

1 in = 25.4 mm

1 in = 2.54 cm

How to Convert Inches to Millimeters

The fastest and simplest way to convert inches to mm (millimeters) is to use this easy formula:

millimeters = inches × 25.4

Since there are 25.4 millimeters in one inch[1], the length in millimeters is up to inches times by 25.4. Thus, the formula to convert inches to millimeters is that the length is multiplied by 25.4.

For example, here's the way to convert 5 inches to millimeters using the formula above.

5" = (5 × 25.4) = 127 mm

How Many Millimeters are in an Inch?


infographic showing how to convert inches to millimeters



What is an Inch?

An inch could be a unit of linear length measure adequate to 1/12 of a foot or 1/36 of a yard. Because the international yard is legally defined to be capable exactly 0.9144 meters, one inch is capable 2.54 centimeters.[2]

The inch could be a US customary and imperial unit of length. Inches are often abbreviated as in; as an example, 1 inch will be written as 1 in.

Inches can even be denoted using the ″ symbol, otherwise called a double-prime. Often a double-quote (") is employed rather than a double-prime for convenience. A double-prime is usually accustomed express 1 in as 1″.

A quarter is .955" in diameter, which is simply smaller than 1"

A quarter is .955" in diameter, which is just smaller than 1"

The standard ruler has 12", and could be a common measuring tool for measuring inches. they're also often measured using tape measures, which commonly are available in lengths from 6' - 35'. Other kinds of measuring devices include scales, calipers, measuring wheels, micrometers, yardsticks, and even lasers.

What is a Millimeter?

One millimeter is adequate to one-thousandth (1/1,000) of a meter, which is defined because the distance light travels in an exceedingly vacuum in an exceedingly 1/299,792,458 second amount.

The millimeter, or millimeter, could be a multiple of the meter, which is that the SI base unit for length. within the system of weights and measures, "milli" is that the prefix for 10-3. Millimeters is abbreviated as mm; for instance, 1 millimeter may be written as 1 mm.

Millimeters are often represented by the littlest ticks on most metric rulers. to induce a point of reference of the scale, the thickness of a US dime is 1.35mm.[3]

We recommend employing a ruler or measuring device for measuring length, which might be found at a neighborhood retailer or home center. Rulers are available in imperial, metric, or combination with both values, so confirm you get the right type for your needs.

Inch to Millimeter Conversion Table

Inch measurements converted to millimeters


1"- 25.4 mm

2"-50.8 mm

3"-76.2 mm

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