| Number | Imperial Standard (swg) | Birmingham Wire (bwg) | ||
| ins | mm | ins | mm | |
| 0 | .324 | 8.23 | .340 | 8.63 |
| 1 | .300 | 7.620 | .300 | 7.62 |
| 2 | .276 | 7.010 | .284 | 7.21 |
| 3 | .252 | 6.400 | .259 | 6.58 |
| 4 | .232 | 5.893 | .238 | 6.05 |
| 5 | .212 | 5.385 | .220 | 5.59 |
| 6 | .192 | 4.877 | .203 | 5.16 |
| 7 | .176 | 4.470 | .180 | 4.57 |
| 8 | .160 | 4.064 | 1.65 | 4.19 |
| 9 | .144 | 3.657 | .148 | 3.76 |
| 10 | .128 | 3.251 | .134 | 3.40 |
| 11 | .116 | 2.946 | .120 | 3.04 |
| 12 | .104 | 2.641 | .109 | 2.77 |
| 13 | .092 | 2.337 | .095 | 2.41 |
| 14 | .080 | 2.032 | .083 | 2.11 |
| 15 | .072 | 1.828 | .072 | 1.83 |
| 16 | .064 | 1.626 | .065 | 1.65 |
| 17 | .056 | 1.422 | .058 | 1.47 |
| 18 | .048 | 1.219 | .049 | 1.24 |
| 19 | .040 | 1.02 | .042 | 1.07 |
| 20 | .036 | .914 | .035 | .888 |
| 21 | .032 | .813 | .032 | .813 |
| 22 | .028 | .711 | .028 | .711 |
| 23 | .024 | .610 | .025 | .635 |
| 24 | .0220 | .559 | .022 | .559 |
| 25 | .020 | .508 | .020 | .508 |
