Table 5. Lumber size conversions

Massachusetts Forest Products Association

 
Fraction (in) Decimal mm
1/16
0.0625
1.59
1/8
0.1250
3.18
3/16
0.1875
4.76
1/4
0.2500
6.35
5/16
0.3125
7.94
3/8
0.3750
9.53
7/16
0.4375
11.11
1/2
0.5000
12.70
9/16
0.5625
14.29
5/8
0.6250
15.88
11/16
0.6875
17.46
3/4
0.7500
19.05
13/16
0.8125
20.64
7/8
0.8750
22.23
15/16
0.9375
23.81
1
1.0000
25.40

 

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