It’s not necessarily the most frequently needed specification, but you might find yourself needing to know the pipe dimensions from time to time. Things like ID, OD, wall thickness for a given NPT pipe size are not obvious without a table to reference.
Schedule 40 Pipe Dimensions
| Nom. Pipe Size (in) |
O.D. |
Average I.D. |
Min. Wall |
Nom. Wt./Ft. |
Max. W.P. PSI |
| 1/8″ |
0.405 |
0.249 |
0.068 |
0.051 |
810 |
| 1/4″ |
0.540 |
0.344 |
0.088 |
0.086 |
780 |
| 3/8″ |
0.675 |
0.473 |
0.091 |
0.115 |
620 |
| 1/2″ |
0.840 |
0.602 |
0.109 |
0.170 |
600 |
| 3/4″ |
1.050 |
0.804 |
0.113 |
0.226 |
480 |
| 1″ |
1.315 |
1.029 |
0.133 |
0.333 |
450 |
| 1-1/4″ |
1.660 |
1.360 |
0.140 |
0.450 |
370 |
| 1-1/2″ |
1.900 |
1.590 |
0.145 |
0.537 |
330 |
| 2″ |
2.375 |
2.047 |
0.154 |
0.720 |
280 |
| 2-1/2″ |
2.875 |
2.445 |
0.203 |
1.136 |
300 |
| 3″ |
3.500 |
3.042 |
0.216 |
1.488 |
260 |
| 3-1/2″ |
4.000 |
3.521 |
0.226 |
1.789 |
240 |
| 4″ |
4.500 |
3.998 |
0.237 |
2.118 |
220 |
| 5″ |
5.563 |
5.016 |
0.258 |
2.874 |
190 |
| 6″ |
6.625 |
6.031 |
0.280 |
3.733 |
180 |
| 8″ |
8.625 |
7.942 |
0.322 |
5.619 |
160 |
| 10″ |
10.750 |
9.976 |
0.365 |
7.966 |
140 |
| 12″ |
12.750 |
11.889 |
0.406 |
10.534 |
130 |
| 14″ |
14.000 |
13.073 |
0.437 |
12.462 |
130 |
| 16″ |
16.000 |
14.940 |
0.500 |
16.286 |
130 |
| 18″ |
18.000 |
16.809 |
0.562 |
20.587 |
130 |
| 20″ |
20.000 |
18.743 |
0.593 |
24.183 |
120 |
| 24″ |
24.000 |
22.544 |
0.687 |
33.652 |
120 |
Schedule 80 Dimensions
| Nom. Pipe Size (in) |
O.D. |
Average I.D. |
Min. Wall |
Nom. Wt./Ft. |
Max. W.P. PSI |
| 1/8″ |
.405 |
.195 |
0.095 |
0.063 |
1230 |
| 1/4″ |
.540 |
.282 |
0.119 |
0.105 |
1130 |
| 3/8″ |
.675 |
.403 |
0.126 |
0.146 |
920 |
| 1/2″ |
.840 |
.526 |
0.147 |
0.213 |
850 |
| 3/4″ |
1.050 |
.722 |
0.154 |
0.289 |
690 |
| 1″ |
1.315 |
.936 |
0.179 |
0.424 |
630 |
| 1-1/4″ |
1.660 |
1.255 |
0.191 |
0.586 |
520 |
| 1-1/2″ |
1.900 |
1.476 |
0.200 |
0.711 |
470 |
| 2″ |
2.375 |
1.913 |
0.218 |
0.984 |
400 |
| 2-1/2″ |
2.875 |
2.290 |
0.276 |
1.500 |
420 |
| 3″ |
3.500 |
2.864 |
0.300 |
2.010 |
370 |
| 3-1/2″ |
4.000 |
3.326 |
0.318 |
2.452 |
350 |
| 4″ |
4.500 |
3.786 |
0.337 |
2.938 |
320 |
| 5″ |
5.563 |
4.768 |
0.375 |
4.078 |
290 |
| 6″ |
6.625 |
5.709 |
0.432 |
5.610 |
280 |
| 8″ |
8.625 |
7.565 |
0.500 |
8.522 |
250 |
| 10″ |
10.750 |
9.493 |
0.593 |
12.635 |
230 |
| 12″ |
12.750 |
11.294 |
0.687 |
17.384 |
230 |
| 14″ |
14.000 |
12.410 |
0.750 |
20.852 |
220 |
| 16″ |
16.000 |
14.213 |
0.843 |
26.810 |
220 |
| 18″ |
18.000 |
16.014 |
0.937 |
33.544 |
220 |
| 20″ |
20.000 |
17.814 |
1.031 |
41.047 |
220 |
| 24″ |
24.000 |
21.418 |
1.218 |
58.233 |
210 |
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