How Do I Select a Marker Size?
Wire Gauge Chart
Brady offers a variety marker sizes for your wire marking needs. Please view the charts listed below to assist you in choosing the minimum recommended label height for your specific type of wire or cable that you are identifying.
Type THW Wire O.D.
| Size AWG. |
O.D. mm (inch) |
Circumference mm (inch) |
Minimum Recommended Label Height |
| 18 | 2.74 (0.108) | 2.64 (0.34) | 12.70 (0.500) |
| 16 | 3.00 (0.118) | 9.42 (0.37) | 12.70 (0.500) |
| 14 | 4.11 (0.162) | 12.91 (0.51) | 19.05 (0.750) |
| 12 | 4.55 (0.179) | 14.29 (0.56) | 25.40 (1.000) |
| 10 | 5.05 (0.199) | 15.86 (0.63) | 25.40 (1.000) |
| 8 | 7.01 (0.276) | 22.01 (0.87) | 38.10 (1.500) |
| 6 | 8.20 (0.323) | 25.75 (1.02) | 38.10 (1.500) |
| 4 | 9.45 (0.372) | 29.67 (1.17) | 44.45 (1.750) |
| 3 | 10.19 (0.401) | 32.00 (1.26) | 50.80 (2.000) |
| 2 | 11.00 (0.433) | 34.54 (1.36) | 50.80 (2.000) |
| 1 | 12.90 (0.508) | 40.51 (1.60) | 63.50 (2.500) |
| 1/0 | 13.95 (0.549) | 43.80 (1.72) | 63.50 (2.500) |
| 2/0 | 15.11 (0.595) | 47.45 (1.87) | 76.20 (3.000) |
| 3/0 | 16.43 (0.647) | 51.59 (2.03) | 76.20 (3.000) |
| 4/0 | 17.91 (0.705) | 56.24 (2.21) | 88.90 (3.500) |
Type THHN Wire O.D.
| Size AWG. |
O.D. mm (inch) |
Circumference mm (inch) |
Minimum Recommended Label Height |
| 18 | 2.26 (0.089) | 7.10 (0.28) | 12.70 (0.500) |
| 16 | 2.54 (0.100) | 7.98 (0.31) | 12.70 (0.500) |
| 14 | 2.67 (0.105) | 8.38 (0.33) | 12.70 (0.500) |
| 12 | 3.10 (0.122) | 9.73 (0.38) | 12.70 (0.500) |
| 10 | 3.89 (0.153) | 12.21 (0.48) | 19.05 (0.750) |
| 8 | 5.54 (0.218) | 17.40 (0.68) | 25.40 (1.000) |
| 6 | 6.53 (0.257) | 20.50 (0.81) | 31.75 (1.250) |
| 4 | 8.33 (0.328) | 26.16 (1.03) | 38.10 (1.500) |
| 3 | 9.04 (0.356) | 28.39 (1.12) | 44.45 (1.750) |
| 2 | 9.86 (0.388) | 30.96 (1.22) | 50.80 (2.000) |
| 1 | 11.43 (0.450) | 35.89 (1.41) | 57.15 (2.250) |
| 1/0 | 12.47 (0.491) | 36.16 (1.54) | 63.50 (2.500) |
| 2/0 | 13.64 (0.537) | 42.83 (1.69) | 63.50 (2.500) |
| 3/0 | 14.94 (0.588) | 46.91 (1.85) | 69.85 (2.750) |
| 4/0 | 16.41 (0.646) | 51.53 (2.03) | 76.20 (3.000) |
Type PVC Wire O.D.
| Size AWG. |
O.D. mm (inch) |
Circumference mm (inch) |
Minimum Recommended Label Height |
| 22 | 1.57 (0.062) | 4.93 (0.19) | 7.62 (0.300) |
| 20 | 1.75 (0.069) | 5.50 (0.22) | 7.62 (0.300) |
| 18 | 2.00 (0.079) | 6.28 (0.25) | 12.70 (0.500) |
| 16 | 2.34 (0.092) | 7.53 (0.29) | 12.70 (0.500) |
| 14 | 3.50 (0.138) | 10.99 (0.43) | 19.05 (0.750) |
| 12 | 4.01 (0.158) | 12.59 (0.50) | 19.05 (0.750) |
| 10 | 4.65 (0.183) | 14.60 (0.57) | 25.40 (1.000) |
| 8 | 6.35 (0.250) | 19.94 (0.79) | 31.75 (1.250) |
Type Teflon Wire O.D.
| Size AWG. |
O.D. mm (inch) |
Circumference mm (inch) |
Minimum Recommended Label Height |
| 22 | 1.52 (0.060) | 4.77 (0.19) | 7.62 (0.300) |
| 20 | 1.73 (0.068) | 5.43 (0.21) | 7.62 (0.300) |
| 18 | 2.01 (0.079) | 6.31 (0.25) | 12.70 (0.500) |
| 16 | 2.26 (0.089) | 7.10 (0.28) | 12.70 (0.500) |
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Brady Worldwide, Inc.