Inches to Millimeters Conversion

How many mm in an inch?

There are 25.4 mm in an inch (1 in = 25.4 mm).

To find out how many millimeters (mm) in "x" inches or inches in "x" millimeters, enter an inch or a millimeter value into the converter and the result will be displayed.

Round:
Enter Inch
Enter Millimeter

Inches to millimeters length units conversion factor is 25.4. To find out how many millimeters in inches multiply the inch value by 25.4.

1 Inch = 25.4 Millimeters

There are 25.4 millimeters in an inch, because for both imperial and US Customary measurement systems, one foot is defined as 30.48 centimeters (or 304.8 millimeters) exactly by an international agreements and there are 12 inches in a foot, that makes 304.8 / 12 = 25.4 mm in an inch.

For example, to find out how many millimeters there are in an inch and a half, multiply the inch value by the conversion factor, that makes 1.5 * 25.4 = 38.1 millimeters in 1.5 inches.

Inch is an imperial and US Customary measurement systems length unit. 1 inch equals to 25.4 millimeters and 2.54 centimeters. The abbreviation is "in".

Millimeter is a metric length unit and equal to one thousandth of a meter. It is used to measure small distances in engineering and machining. The abbreviation is "mm".

Create Custom Conversion Table
To create your own custom conversion table click "Create Table" botton. To change values, you may enter a "Start" value (1, 2.5, 5 etc), select a an "Increment" value (0.01, 5, 100 etc) and select an "Accuracy" value to round the result.

Inches to Millimeters Conversion Table

InchMillimeterInchMillimeterInchMillimeterInchMillimeter
1 25.4 26 660.4 51 1295.4 76 1930.4
2 50.8 27 685.8 52 1320.8 77 1955.8
3 76.2 28 711.2 53 1346.2 78 1981.2
4 101.6 29 736.6 54 1371.6 79 2006.6
5 127 30 762 55 1397 80 2032
6 152.4 31 787.4 56 1422.4 81 2057.4
7 177.8 32 812.8 57 1447.8 82 2082.8
8 203.2 33 838.2 58 1473.2 83 2108.2
9 228.6 34 863.6 59 1498.6 84 2133.6
10 254 35 889 60 1524 85 2159
11 279.4 36 914.4 61 1549.4 86 2184.4
12 304.8 37 939.8 62 1574.8 87 2209.8
13 330.2 38 965.2 63 1600.2 88 2235.2
14 355.6 39 990.6 64 1625.6 89 2260.6
15 381 40 1016 65 1651 90 2286
16 406.4 41 1041.4 66 1676.4 100 254
17 431.8 42 1066.8 67 1701.8 125 3175
18 457.2 43 1092.2 68 1727.2 150 381
19 482.6 44 1117.6 69 1752.6 175 4445
20 508 45 1143 70 1778 200 508
21 533.4 46 1168.4 71 1803.4 250 635
22 558.8 47 1193.8 72 1828.8 300 762
23 584.2 48 1219.2 73 1854.2 500 1270
24 609.6 49 1244.6 74 1879.6 750 1905
25 635 50 127 75 1905 1000 2540