Allen Wrench Size Imperial Decimal Equivalent (inches)
0.7 mm0.0276
0.028"0.0280
1/32"0.0313
0.035"0.0350
0.9 mm0.0354
3/64"0.0469
0.05"0.0500
1.3 mm0.0512
1.5 mm0.0591
1/16"0.0625
5/64"0.0781
2 mm0.0787
3/32"0.0938
2.5 mm0.0984
7/64"0.1094
3 mm0.1181
1/8"0.1250
3.5 mm0.1378
9/64"0.1406
5/32"0.1563
4 mm0.1575
4.5 mm0.1772
3/16"0.1875
5 mm0.1969
5.5 mm0.2165
7/32"0.2188
6 mm0.2362
1/4"0.2500
7 mm0.2756
5/16"0.3125
8 mm0.3150
9 mm0.3543
3/8"0.3750
10 mm0.3937
7/16"0.4375
12 mm0.4724
1/2"0.5000
14 mm0.5512
9/16"0.5625
5/8"0.6250
17 mm0.6693
11/16"0.6875
19 mm0.7480
3/4"0.7500
22 mm0.8661
7/8"0.8750
1"1.0000

Common sizes in typical mechanic's sets only

Allen Wrench Size Imperial Decimal Equivalent (inches)
0.05"0.0500
1.5 mm0.0591
1/16"0.0625
5/64"0.0781
2 mm0.0787
3/32"0.0938
2.5 mm0.0984
7/64"0.1094
3 mm0.1181
1/8"0.1250
3.5 mm0.1378
9/64"0.1406
5/32"0.1563
4 mm0.1575
4.5 mm0.1772
3/16"0.1875
5 mm0.1969
5.5 mm0.2165
7/32"0.2188
6 mm0.2362
1/4"0.2500
7 mm0.2756
5/16"0.3125
8 mm0.3150
9 mm0.3543
3/8"0.3750
10 mm0.3937