# Wire Gauge Size and Resistance Calculator

Calculate the diameter, cross-sectional area, and resistance of wire given its gauge or find the gauge of a wire given a diameter.

## Wire Gauge Calculator

## Wire Gauge Formulas

Wire gauge is a standard unit for measuring the diameter of the wire and American wire gauge, or AWG, is the standard used in North America. The diameter and cross-sectional area of a wire can be found using the wire gauge and a few simple formulas.

### Wire Diameter

The formula to find the diameter of the wire in inches is:

diameter (in) = .005 × 92^{(36 – AWG) ÷ 39}

The formula to find the diameter of the wire in millimeters is:

diameter (mm) = .127 × 92^{(36 – AWG) ÷ 39}

#### Steps to Find the Diameter

**First** – find the exponent in the equation by subtracting the wire gauge from 36 then dividing by 39.

Finding the exponent for 00, 000, and 0000 gauge wire is slightly different. Substitute -1, -2, and -3 for the gauge in the formula above instead of the AWG value.

**Second** – find 92 to the power calculated in the previous step.

**Third** – multiply the value from the second step by either .005 inches or .127 mm to find the diameter of the wire in inches or millimeters respectively.

### Wire Cross-Sectional Area

The formula to find the cross-sectional area of the wire in kilo-circular mils, or kcmil, is:

area (kcmil) = 1000 × diameter^{2}

The formula to find the cross-sectional area of the wire in square millimeters is:

area (mm^{2}) = (π ÷ 4) × diameter^{2}

#### Steps to Find the Cross-Sectional Area

**First** – find the diameter of the wire. Use the formula above to calculate the width if the AWG is known.

**Second** – multiply the diameter by 1000 to find the area in kcmil or by (3.1415 ÷ 4) to calculate square millimeters.

## Wire Gauge Diameter, Area, and Resistance Chart

AWG | Diameter | Cross-Sectional Area | Resistance | |||
---|---|---|---|---|---|---|

(inches) | (mm) | (kcmil) | (mm^{2}) |
Ohms per 1000ft | Ohms per 1000m | |

0000 (4/0) | 0.46 | 11.684 | 211.6 | 107.22 | 0.049 | 0.1608 |

000 (3/0) | 0.4096 | 10.405 | 167.81 | 85.029 | 0.0618 | 0.2028 |

00 (2/0) | 0.3648 | 9.266 | 133.08 | 67.431 | 0.0779 | 0.2557 |

0 (1/0) | 0.3249 | 8.251 | 105.53 | 53.475 | 0.0983 | 0.3224 |

1 | 0.2893 | 7.348 | 83.693 | 42.408 | 0.1239 | 0.4066 |

2 | 0.2576 | 6.544 | 66.371 | 33.631 | 0.1563 | 0.5127 |

3 | 0.2294 | 5.827 | 52.635 | 26.67 | 0.197 | 0.6464 |

4 | 0.2043 | 5.189 | 41.741 | 21.151 | 0.2485 | 0.8152 |

5 | 0.1819 | 4.621 | 33.102 | 16.773 | 0.3133 | 1.028 |

6 | 0.162 | 4.115 | 26.251 | 13.302 | 0.3951 | 1.296 |

7 | 0.1443 | 3.665 | 20.818 | 10.549 | 0.4982 | 1.634 |

8 | 0.1285 | 3.264 | 16.51 | 8.366 | 0.6282 | 2.061 |

9 | 0.1144 | 2.906 | 13.093 | 6.634 | 0.7921 | 2.599 |

10 | 0.1019 | 2.588 | 10.383 | 5.261 | 0.9988 | 3.277 |

11 | 0.0907 | 2.305 | 8.234 | 4.172 | 1.26 | 4.132 |

12 | 0.0808 | 2.053 | 6.53 | 3.309 | 1.588 | 5.211 |

13 | 0.072 | 1.828 | 5.178 | 2.624 | 2.003 | 6.571 |

14 | 0.0641 | 1.628 | 4.107 | 2.081 | 2.525 | 8.285 |

15 | 0.0571 | 1.45 | 3.257 | 1.65 | 3.184 | 10.448 |

16 | 0.0508 | 1.291 | 2.583 | 1.309 | 4.015 | 13.174 |

17 | 0.0453 | 1.15 | 2.048 | 1.038 | 5.063 | 16.612 |

18 | 0.0403 | 1.024 | 1.624 | 0.823 | 6.385 | 20.948 |

19 | 0.0359 | 0.9116 | 1.288 | 0.6527 | 8.051 | 26.415 |

20 | 0.032 | 0.8118 | 1.022 | 0.5176 | 10.152 | 33.308 |

21 | 0.0285 | 0.7229 | 0.8101 | 0.4105 | 12.802 | 42.001 |

22 | 0.0253 | 0.6438 | 0.6424 | 0.3255 | 16.143 | 52.962 |

23 | 0.0226 | 0.5733 | 0.5095 | 0.2582 | 20.356 | 66.784 |

24 | 0.0201 | 0.5106 | 0.404 | 0.2047 | 25.668 | 84.213 |

25 | 0.0179 | 0.4547 | 0.3204 | 0.1624 | 32.367 | 106.19 |

26 | 0.0159 | 0.4049 | 0.2541 | 0.1288 | 40.814 | 133.9 |

27 | 0.0142 | 0.3606 | 0.2015 | 0.1021 | 51.466 | 168.85 |

28 | 0.0126 | 0.3211 | 0.1598 | 0.081 | 64.897 | 212.92 |

29 | 0.0113 | 0.2859 | 0.1267 | 0.0642 | 81.833 | 268.48 |

30 | 0.01 | 0.2546 | 0.1005 | 0.0509 | 103.19 | 338.55 |

31 | 0.008928 | 0.2268 | 0.0797 | 0.0404 | 130.12 | 426.9 |

32 | 0.00795 | 0.2019 | 0.0632 | 0.032 | 164.08 | 538.32 |

33 | 0.00708 | 0.1798 | 0.0501 | 0.0254 | 206.9 | 678.8 |

34 | 0.006305 | 0.1601 | 0.0398 | 0.0201 | 260.9 | 855.96 |

35 | 0.005615 | 0.1426 | 0.0315 | 0.016 | 328.98 | 1,079.3 |

36 | 0.005 | 0.127 | 0.025 | 0.0127 | 414.84 | 1,361 |

37 | 0.004453 | 0.1131 | 0.0198 | 0.01 | 523.1 | 1,716.2 |

38 | 0.003965 | 0.1007 | 0.0157 | 0.007967 | 659.62 | 2,164.1 |

39 | 0.003531 | 0.0897 | 0.0125 | 0.006318 | 831.77 | 2,728.9 |

40 | 0.003145 | 0.0799 | 0.009888 | 0.00501 | 1,048.8 | 3,441.1 |

Also see our electricity cost calculator and our lighting cost calculator to before you plan your next electrical project.