Inches Conversion

Tape measures can be used to measure units of length, and a calculator can be used to convert to another unit

The inch is a unit used to measure length. Use one of the conversion calculators below to convert to another unit of measure, or read on to learn more about inches.

Inch Conversion Calculators

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US Customary & Imperial Units
SI Units

Inch Definition and Usage

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

The inch is a US customary and imperial unit of length. Inches can be abbreviated as in, for example 1 inch can be written as 1 in.

Inches can also be denoted using the symbol, otherwise know as a double-prime. Often a double-quote (") is used instead of a double-prime for convenience. Using the double-prime, 1 in can be written as 1″.

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

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

You'll probably also be interested in our inch fraction calculator, which converts inch values from decimal to a fraction and solves inch fractions.

Inches Measurement Conversion Table

Common inch values and equivalent imperial and metric length measurements
inches miles yards feet kilometers meters centimeters millimeters micrometers nanometers
1" 0.000015783 mi 0.027778 yd 0.083333' 0.0000254 km 0.0254 m 2.54 cm 25.4 mm 25,400 µm 25,400,000 nm
2" 0.000031566 mi 0.055556 yd 0.166667' 0.0000508 km 0.0508 m 5.08 cm 50.8 mm 50,800 µm 50,800,000 nm
3" 0.000047348 mi 0.083333 yd 0.25' 0.0000762 km 0.0762 m 7.62 cm 76.2 mm 76,200 µm 76,200,000 nm
4" 0.000063131 mi 0.111111 yd 0.333333' 0.000102 km 0.1016 m 10.16 cm 101.6 mm 101,600 µm 101,600,000 nm
5" 0.000078914 mi 0.138889 yd 0.416667' 0.000127 km 0.127 m 12.7 cm 127 mm 127,000 µm 127,000,000 nm
6" 0.000094697 mi 0.166667 yd 0.5' 0.000152 km 0.1524 m 15.24 cm 152.4 mm 152,400 µm 152,400,000 nm
7" 0.00011 mi 0.194444 yd 0.583333' 0.000178 km 0.1778 m 17.78 cm 177.8 mm 177,800 µm 177,800,000 nm
8" 0.000126 mi 0.222222 yd 0.666667' 0.000203 km 0.2032 m 20.32 cm 203.2 mm 203,200 µm 203,200,000 nm
9" 0.000142 mi 0.25 yd 0.75' 0.000229 km 0.2286 m 22.86 cm 228.6 mm 228,600 µm 228,600,000 nm
10" 0.000158 mi 0.277778 yd 0.833333' 0.000254 km 0.254 m 25.4 cm 254 mm 254,000 µm 254,000,000 nm
11" 0.000174 mi 0.305556 yd 0.916667' 0.000279 km 0.2794 m 27.94 cm 279.4 mm 279,400 µm 279,400,000 nm
12" 0.000189 mi 0.333333 yd 1' 0.000305 km 0.3048 m 30.48 cm 304.8 mm 304,800 µm 304,800,000 nm
13" 0.000205 mi 0.361111 yd 1.083333' 0.00033 km 0.3302 m 33.02 cm 330.2 mm 330,200 µm 330,200,000 nm
14" 0.000221 mi 0.388889 yd 1.166667' 0.000356 km 0.3556 m 35.56 cm 355.6 mm 355,600 µm 355,600,000 nm
15" 0.000237 mi 0.416667 yd 1.25' 0.000381 km 0.381 m 38.1 cm 381 mm 381,000 µm 381,000,000 nm
16" 0.000253 mi 0.444444 yd 1.333333' 0.000406 km 0.4064 m 40.64 cm 406.4 mm 406,400 µm 406,400,000 nm
17" 0.000268 mi 0.472222 yd 1.416667' 0.000432 km 0.4318 m 43.18 cm 431.8 mm 431,800 µm 431,800,000 nm
18" 0.000284 mi 0.5 yd 1.5' 0.000457 km 0.4572 m 45.72 cm 457.2 mm 457,200 µm 457,200,000 nm
19" 0.0003 mi 0.527778 yd 1.583333' 0.000483 km 0.4826 m 48.26 cm 482.6 mm 482,600 µm 482,600,000 nm
20" 0.000316 mi 0.555556 yd 1.666667' 0.000508 km 0.508 m 50.8 cm 508 mm 508,000 µm 508,000,000 nm

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References

  1. National Institute of Standards and Technology, Checking the Net Contents of Packaged Goods, Handbook 133 - 2019 Edition, https://nvlpubs.nist.gov/nistpubs/hb/2019/NIST.HB.133-2019.pdf