HesapHanem

AWG to mm² Wire Size Converter

Enter a wire gauge or area and choose a conversion direction.

How it is calculated

Choose a direction, then enter one number. From AWG to area the tool uses A = 0.012668 × 92(36 − AWG) / 19.5, where A is the conductor cross-section in mm². From area to AWG it inverts this: AWG = 36 − 19.5 × ln(A / 0.012668) / ln(92). The conductor diameter is then d = √(4A / π) in mm, which treats the wire as a solid round conductor. The AWG figure is shown with one decimal and areas and diameters with four. The area given in mm² must be greater than zero. An AWG entry is not limited, so values of 0 or below also compute. The result is the geometric size only, not a current rating.

Worked example

Convert 12 AWG to area. The exponent is (36 − 12) / 19.5 = 1.2308. Then 92 to that power is about 261.2, and multiplying by 0.012668 gives 3.3089. The tool shows 3.3089 mm². The diameter is √(4 × 3.3089 / π) = 2.0526 mm. Run the other direction with 2.5 mm² and the tool gives 13.2 AWG, with a diameter of 1.7841 mm. That is between 13 and 14 AWG, so you would pick a nearby real size.

Try this example →

Common mistakes

  • Leaving the direction on AWG to mm² when typing an area. 2.5 would be read as gauge 2.5 and give about 29.95 mm².
  • Assuming a bigger AWG number is a bigger wire. It is the opposite: 12 AWG is thicker than 20 AWG.
  • Using the result as the wire's current rating. The tool gives only geometry; ampacity depends on insulation, temperature and installation.
  • Treating the AWG result in the mm² to AWG direction (for example 13.2) as an orderable size. Real gauges are whole numbers, so round to a standard neighbour and check which side is safer.
  • Applying the result to stranded wire. The diameter assumes one solid round conductor, so a stranded cable of the same copper area is somewhat thicker overall.

Sources

About this calculator

American Wire Gauge (AWG) is the sizing standard used across North America for round, solid, non-ferrous conductor wire, while most of the rest of the world specifies wire by its cross-sectional area in square millimeters — a mismatch that trips up anyone sourcing parts, reading a datasheet, or wiring equipment across regions. AWG size follows a geometric progression where the diameter in inches is d = 0.005 × 92^((36−n)/39) for gauge n, so each drop of 3 gauge numbers roughly doubles the cross-sectional area (and every 6-gauge drop doubles the diameter).

This calculator converts a given AWG size to its equivalent area in mm² (or the reverse), and also reports the conductor diameter, using the standard AWG-to-metric relationship — the same reference electricians, cable manufacturers, and hobbyists use to match a European mm² cable spec to its closest AWG equivalent, or to check a wire’s current-carrying capacity against ampacity tables that are published in one unit or the other.

Was this helpful?

You can pick up to 3 reactions.

Comments (1)

  • Editorial team

    The big sizes are written 1/0, 2/0, 3/0 and 4/0, and there is no slash key to type here. Enter them as 0, -1, -2 and -3 instead: -3 gives 107.22 mm², which is the 4/0 conductor. The result then reads as a negative AWG number, so match it back to the slash notation yourself. As a sanity check, 12 AWG is 3.31 mm² and 9 AWG is 6.63 mm². Which sizes do you convert most often?

Popular calculators

Loan Calculator

Monthly payment, total interest and full amortization schedule.

Percentage Calculator

Percent change, percent of, and ratio calculations.

Discount Calculator

Calculate final price, savings, and discount amount.

BMI Calculator

Body mass index from height and weight (metric or imperial).

Age Calculator

Compute your exact age in years, months and days from a birth date.

Compound Interest Calculator

Calculate the final amount and interest earned with compounding.

All Calculators