Look up any AWG size in millimetres, mm², inches, and kcmil with a nearby reference table for wire and cable comparisons. Use it to test different inputs quickly, compare outcomes, and understand the main factors behind the result before moving on to related tools or deeper guidance.
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AWG to mm calculator Convert an American Wire Gauge size into diameter in millimetres, cross-sectional area in mm², inch diameter, and circular-mil scale without manually working from the AWG formula.
Common sizes
Method note
AWG is a discrete standard series for solid round conductors. The calculator follows the published AWG diameter relationship, then derives mm² area from the circular cross-section. Stranded cables can have the same conductor area but a larger overall outside diameter because of air gaps and insulation.
Gauge conversion
AWG 12 = 2.05 mm
AWG 12 corresponds to a bare-conductor diameter of 2.05 mm, a cross-sectional area of 3.31 mm², and about 6.53 kcmil.
Diameter
2.05 mm
Diameter in inches
0.08 in
Area
3.31 mm²
Circular area
6.53 kcmil
Formula used
d(in) = 0.005 × 92^((36 − AWG) / 39)
The AWG series is logarithmic, so each step changes diameter by a fixed ratio rather than by a fixed linear amount.
Nearby reference sizes
Gauge
mm
in
mm²
kcmil
AWG 10
2.59
0.1
5.26
10.38
AWG 11
2.3
0.09
4.17
8.23
AWG 12
2.05
0.08
3.31
6.53
AWG 13
1.83
0.07
2.62
5.18
AWG 14
1.63
0.06
2.08
4.11
How to use this result
Use the mm diameter when you need a dimensional comparison, use mm² or kcmil when comparing conductor cross-section, and use a dedicated wire-size or ampacity calculator if the next question is voltage drop, insulation, or allowable current.
AWG to mm calculator: convert wire gauge to diameter, mm², and kcmil
An AWG to mm calculator converts American Wire Gauge sizes into metric diameter and cross-sectional area so you can compare North American wire sizes with metric cable specs. It is most useful when a datasheet, cable gland, connector, or wiring plan switches between AWG, millimetres, mm², and circular-mil language.
What this AWG to mm calculator helps you compare
American Wire Gauge is a discrete standard series, not a continuous measurement scale. Each AWG step maps to a specific conductor diameter, so the practical task is usually a lookup and comparison exercise rather than a free-form unit conversion.
This calculator turns an AWG size into bare-conductor diameter in millimetres, the equivalent cross-sectional area in mm², diameter in inches, and circular area in kcmil. That makes it easier to compare supplier drawings, connector ranges, and wire-size tables that use different conventions.
It also handles the larger conductor labels that often confuse first-time users: 1/0, 2/0, 3/0, and 4/0. Those are part of the same AWG system and appear here in the familiar slash notation instead of making you remember the negative-number mapping behind the scenes.
The AWG formulas behind the table
The AWG system is logarithmic. Each step changes diameter by a fixed ratio, which is why the difference between adjacent gauges gets smaller as the wire gets thinner. The standard diameter relationship is usually written in inches first, then converted into millimetres for metric work.
Once diameter is known, the cross-sectional area follows from the circle-area formula. This is the cleanest way to connect AWG size with the mm² values commonly used in European and international cable specifications.
d(in) = 0.005 × 92^((36 − AWG) / 39)
Standard AWG diameter relationship in inches for solid round conductors.
d(mm) = 0.127 × 92^((36 − AWG) / 39)
The same diameter relationship expressed directly in millimetres.
A(mm²) = π × (d / 2)²
Cross-sectional area derived from the conductor diameter in millimetres.
Worked example: AWG 12 to metric
Suppose you need the metric equivalent of AWG 12 for a connector or cable gland that lists metric conductor sizes. The AWG relationship gives a bare-conductor diameter of about 2.053 mm. Applying the circle-area formula to that diameter produces about 3.309 mm².
That does not mean every insulated AWG 12 cable will measure 2.053 mm across the outside. Insulation thickness, strand count, and construction all change the external cable size. The AWG-to-mm result describes the conductor size itself, which is why it should be paired with the manufacturer’s overall cable diameter when you are checking glands, sleeves, or conduit fill.
What this converter does not decide for you
This page converts wire-gauge size only. It does not decide whether a conductor is suitable for a given current, voltage drop, insulation class, ambient temperature, or installation method. Those questions belong to wire-size and ampacity calculations, not to a pure gauge conversion.
It also assumes the published AWG standard for solid round conductors. Stranded conductors can share the same nominal area while having a slightly different effective geometry or outside diameter, so always confirm the cable construction details if the mechanical fit matters.
Not as a naming system. AWG and mm² are different standards, and the metric area is derived from the AWG diameter relationship rather than being the original naming basis. In practice, AWG 12 corresponds to about 3.309 mm² of conductor area, which is close enough for comparison work but should still be treated as a standard-size translation rather than a literal renaming.
Why do larger wires have smaller AWG numbers?
Because AWG numbering runs in the opposite direction from wire thickness. As the conductor gets larger, the AWG number falls. That is why AWG 4 is thicker than AWG 12, and why the very largest common sizes continue into 1/0, 2/0, 3/0, and 4/0 rather than into larger positive integers.
Can I use AWG to mm conversion to choose a breaker or fuse?
No. Gauge conversion only tells you the conductor size relationship. Breaker and fuse selection also depend on conductor material, insulation temperature rating, installation method, ambient conditions, termination limits, code rules, and the actual load profile. Use this page for size comparison, then move to ampacity and voltage-drop checks for design decisions.
Why can a stranded cable look thicker than the AWG diameter result?
Because the AWG diameter here refers to the conductor equivalent, not the finished outside cable diameter. Real cables add insulation, jackets, and sometimes gaps between strands, so the physical outside measurement is often much larger than the bare AWG conductor diameter listed by the conversion formula.
