Reference Guide: Pipe Size Charts
In North America, nominal pipe size (NPS) is the standard for identifying pipe sizes. Outside of North America, pipes are identified by nominal diameter, which approximately equates to the outer diameter (OD) of the pipe in millimeters.
Note that an NPS below 14 approximately refers to the diameter of a pipe measured from the center of the wall material to the opposing side center of the wall material, while an NPS 14 or greater matches the outside diameter of the pipe precisely.
While NPS defines the OD of a pipe, the pipe schedule is also needed to determine other variants, such as pipe wall thickness and inner diameter (ID). The most prevalent schedule sizes are Schedule 40 and Schedule 80. However, a piping project may stipulate higher schedule numbers.
Use APP's pipe size charts below to quickly reference key measurements for:
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Pipe Dimension Definitions
Pipe Wall Thickness Chart
NPS | O.D. | I.D. - Schedule 40 | Wall Thickness - Schedule 40 | I.D. - Scheduled 80 | Wall Thickness - Schedule 80 | |||||||
in. | mm | in. | mm | in. | mm | in. | mm | in. | mm | in. | mm | |
1/8 | 0.125 | 3.175 | 0.405 | 10.287 | 0.229 | 5.8166 | 0.068 | 1.7272 | 0.175 | 4.445 | 0.095 | 2.413 |
1/4 | 0.25 | 6.35 | 0.54 | 13.716 | 0.324 | 8.2296 | 0.088 | 2.2352 | 0.262 | 6.6548 | 0.119 | 3.0226 |
3/8 | 0.375 | 9.525 | 0.675 | 17.145 | 0.453 | 11.5062 | 0.091 | 2.3114 | 0.383 | 9.7282 | 0.126 | 3.2004 |
1/2 | 0.5 | 12.7 | 0.84 | 21.336 | 0.582 | 14.7828 | 0.109 | 2.7686 | 0.506 | 12.8524 | 0.147 | 3.7338 |
3/4 | 0.75 | 19.05 | 1.05 | 26.67 | 0.784 | 19.9136 | 0.113 | 2.8702 | 0.702 | 17.8308 | 0.154 | 3.9116 |
1 | 1 | 25.4 | 1.315 | 33.401 | 1.009 | 25.6286 | 0.133 | 3.3782 | 0.915 | 23.241 | 0.179 | 4.5466 |
1 1/4 | 1.25 | 31.75 | 1.66 | 42.164 | 1.34 | 34.036 | 0.14 | 3.556 | 1.232 | 31.2928 | 0.191 | 4.8514 |
1 1/2 | 1.5 | 38.1 | 1.9 | 48.26 | 1.57 | 39.878 | 0.145 | 3.683 | 1.452 | 36.8808 | 0.2 | 5.08 |
2 | 2 | 50.8 | 2.375 | 60.325 | 2.027 | 51.4858 | 0.154 | 3.9116 | 1.887 | 47.9298 | 0.218 | 5.5372 |
2 1/2 | 2.5 | 63.5 | 2.875 | 73.025 | 2.421 | 61.4934 | 0.203 | 5.1562 | 2.257 | 57.3278 | 0.276 | 7.0104 |
3 | 3 | 76.2 | 3.5 | 88.9 | 3.016 | 76.6064 | 0.216 | 5.4864 | 2.828 | 71.8312 | 0.3 | 7.62 |
3 1/2 | 3.5 | 88.9 | 4 | 101.6 | 3.494 | 88.7476 | 0.226 | 5.7404 | 3.288 | 83.5152 | 0.318 | 8.0772 |
4 | 4 | 101.6 | 4.5 | 114.3 | 3.97 | 100.838 | 0.237 | 6.0198 | 3.746 | 95.1484 | 0.337 | 8.5598 |
4 1/2 | 4.5 | 114.3 | 5 | 127 | 4.985 | 126.619 | 4.723 | 119.9642 | ||||
5 | 5 | 127 | 5.563 | 141.3002 | 5.997 | 152.3238 | 0.258 | 6.5532 | 5.657 | 143.6878 | 0.375 | 9.525 |
6 | 6 | 152.4 | 6.625 | 168.275 | 7.903 | 200.7362 | 0.28 | 7.112 | 7.505 | 190.627 | 0.432 | 10.9728 |
7 | 7 | 177.8 | 7.625 | 193.675 | 9.932 | 252.2728 | 0.301 | 7.6454 | 9.422 | 239.3188 | ||
8 | 8 | 203.2 | 8.625 | 219.075 | 11.84 | 300.736 | 0.322 | 8.1788 | 11.212 | 284.7848 | 0.5 | 12.7 |
10 | 10 | 254 | 10.75 | 273.05 | 0.365 | 9.271 | 0.593 | 15.0622 | ||||
12 | 12 | 304.8 | 12.75 | 323.85 | 0.365 | 9.271 | 0.687 | 17.4498 | ||||
14 | 14 | 355.6 | 14 | 355.6 | 0.437 | 11.0998 | 0.75 | 19.05 | ||||
16 | 16 | 406.4 | 16 | 406.4 | 0.5 | 12.7 | 0.843 | 21.4122 | ||||
18 | 18 | 457.2 | 18 | 457.2 | 0.5 | 12.7 | 0.937 | 23.7998 | ||||
20 | 20 | 508 | 20 | 508 | 0.593 | 15.0622 | 1.031 | 26.1874 | ||||
22 | 22 | 558.8 | 22 | 558.8 | 1.125 | 28.575 | ||||||
24 | 24 | 609.6 | 24 | 609.6 | 0.687 | 17.4498 | 1.218 | 30.9372 | ||||
26 | 26 | 660.4 | 26 | 660.4 | ||||||||
28 | 28 | 711.2 | 28 | 711.2 | ||||||||
30 | 30 | 762 | 30 | 762 | ||||||||
32 | 32 | 812.8 | 32 | 812.8 | 0.688 | 17.4752 |
Copper Nickel Pipe Size Chart
90/10 | 90/10 70/30 | 70/30 | ||||||||||||||
NPS | O.D. | CL 50 Wall | CL 200 Wall | CL 700 Wall | CL 1650 Wall | CL 3300 Wall | CL 6000 Wall | |||||||||
in. | mm | in. | mm | in. | mm | in. | mm | in. | mm | in. | mm | in. | mm | in. | mm | |
1/4 OD | 0.25 | 6.35 | 0.035 | 0.889 | 0.035 | 0.889 | 0.058 | 1.4732 | ||||||||
1/8 | 0.125 | 6.35 | 0.405 | 10.287 | 0.065 | 1.651 | 0.058 | 1.4732 | 0.095 | 2.413 | ||||||
1/4 | 0.25 | 9.525 | 0.54 | 13.716 | 0.065 | 1.651 | 0.065 | 1.651 | 0.042 | 1.0668 | 0.072 | 1.8288 | 0.12 | 3.048 | ||
3/8 | 0.375 | 12.7 | 0.675 | 17.145 | 0.065 | 1.651 | 0.072 | 1.8288 | 0.049 | 1.2446 | 0.095 | 2.413 | 0.148 | 3.7592 | ||
1/2 | 0.5 | 19.05 | 0.84 | 21.336 | 0.065 | 1.651 | 0.072 | 1.8288 | 0.058 | 1.4732 | 0.12 | 3.048 | 0.203 | 5.1562 | ||
3/4 | 0.75 | 25.4 | 1.05 | 26.67 | 0.065 | 1.651 | 0.083 | 2.1082 | 0.083 | 2.1082 | 0.148 | 3.7592 | 0.238 | 6.0452 | ||
1 | 1 | 31.75 | 1.315 | 33.401 | 0.065 | 1.651 | 0.095 | 2.413 | 0.095 | 2.413 | 0.18 | 4.572 | 0.3 | 7.62 | ||
1 1/4 | 1.25 | 38.1 | 1.66 | 42.164 | 0.072 | 1.8288 | 0.095 | 2.413 | 0.12 | 3.048 | 0.22 | 5.588 | 0.38 | 9.652 | ||
1 1/2 | 1.5 | 50.8 | 1.9 | 48.26 | 0.072 | 1.8288 | 0.109 | 2.7686 | 0.134 | 3.4036 | 0.25 | 6.35 | 0.425 | 10.795 | ||
2 | 2 | 63.5 | 2.375 | 60.325 | 0.083 | 2.1082 | 0.12 | 3.048 | 0.165 | 4.191 | 0.34 | 8.636 | 0.52 | 13.208 | ||
2 1/2 | 2.5 | 76.2 | 2.875 | 73.025 | 0.083 | 2.1082 | 0.134 | 3.4036 | 0.203 | 5.1562 | 0.38 | 9.652 | ||||
3 | 3 | 88.9 | 3.5 | 88.9 | 0.095 | 2.413 | 0.165 | 4.191 | 0.25 | 6.35 | 0.457 | 11.6078 | ||||
3 1/2 | 3.5 | 101.6 | 4 | 101.6 | 0.095 | 2.413 | 0.18 | 4.572 | 0.284 | 7.2136 | ||||||
4 | 4 | 114.3 | 4.5 | 114.3 | 0.109 | 2.7686 | 0.203 | 5.1562 | 0.34 | 8.636 | ||||||
4 1/2 | 4.5 | 127 | 5 | 127 | 0.109 | 2.7686 | ||||||||||
5 | 5 | 152.4 | 5.563 | 141.3002 | 0.125 | 3.175 | 0.22 | 5.588 | 0.425 | 10.795 | ||||||
6 | 6 | 177.8 | 6.625 | 168.275 | 0.134 | 3.4036 | 0.259 | 6.5786 | ||||||||
7 | 7 | 203.2 | 7.625 | 193.675 | 0.14 | 3.556 | 0.284 | 7.2136 | ||||||||
8 | 8 | 228.6 | 8.625 | 219.075 | 0.151 | 3.8354 | 0.34 | 8.636 | ||||||||
9 | 9 | 254 | 9.625 | 244.475 | 0.187 | 4.7498 | 0.34 | 8.636 | ||||||||
10 | 10 | 304.8 | 10.75 | 273.05 | 0.134 | 3.4036 | 0.187 | 4.7498 | 0.38 | 9.652 | ||||||
12 | 12 | 355.6 | 12.75 | 323.85 | 0.156 | 3.9624 | 0.25 | 6.35 | 0.454 | 11.5316 | ||||||
14 | 14 | 406.4 | 14 | 355.6 | 0.165 | 4.191 | 0.25 | 6.35 | ||||||||
16 | 16 | 457.2 | 16 | 406.4 | 0.165 | 4.191 | 0.25 | 6.35 | ||||||||
18 | 18 | 508 | 18 | 457.2 | 0.18 | 4.572 | 0.25 | 6.35 | ||||||||
20 | 20 | 0 | 20 | 508 | 0.18 | 4.572 | 0.25 | 6.35 |