AWG to mm²: wire size, without the guesswork

Area excludes insulation. Diameter refers to a solid round conductor. Scroll inside the table for all sizes.

Values use the formula above. ASTM B258 covers nominal diameters and areas of solid round AWG conductors. Use the cable specification for actual construction and tolerances.

Metal cross-sectional area mm²

The area occupied by the conductor metal. For a round solid wire, calculate it from the bare diameter. For round strands, add the individual strand areas; the spaces between them do not count.

Bare conductor diameter mm

The diameter of the solid wire, or the outside envelope of a stranded bundle. A bundle includes inter-strand gaps, so its envelope is larger than an equal-area solid circle.

Insulated core diameter mm

The conductor plus its individual insulation. This dimension can matter at an insulation crimp or an individual wire seal, where fitted.

Overall cable diameter mm

The outside of the complete cable jacket. This is the dimension to compare with a cable gland or backshell’s stated clamping range.

Two cables with the same conductor size can have different overall diameters because their insulation, core count, screening and jacket constructions differ. Measuring the jacket with calipers does not reveal the AWG inside it.

A conversion table and a cable catalog may be answering different questions. One gives the geometric area associated with a gauge; the other may list nominal product sizes or compare sizes against electrical requirements.

LAPP’s T16 technical table separates geometric conversion from metric nominal sizes that meet stated electrical requirements. Its two columns therefore need not contain the same number. That comparison is not permission to substitute any cable with a nearby nominal area.

If a drawing specifies 24 AWG, keep that requirement attached to the wire construction and applicable specification. If it specifies 0.25 mm², select against that requirement. A dual-marked product should be assessed using its own documentation, including conductor resistance and termination requirements; the slash between two designations is not necessarily an exact mathematical equality.

Metric standards also have defined scopes. IEC 60228:2023 covers nominal cross-sections from 0.5 to 3,500 mm² for conductors in power cables and cords, and excludes telecommunication conductors. Do not assume every smaller metric wire size falls within that standard.

For equal-diameter circular strands, use A = strand count × π × strand diameter² / 4. Here, 7 × π × 0.20² / 4 ≈ 0.220 mm². Applying the solid-circle formula to the entire 0.600 mm envelope would count the gaps as metal.

A real example shows why this distinction matters. TE lists 55FA0514-24-7L as 24 AWG with 19 strands, a conductor diameter range of 0.55–0.63 mm and an outside cable diameter of 1.14 mm. Those are separate fields on that product page; the calculator’s approximately 0.511 mm solid-wire reference does not replace either diameter.

For example, a Renhotec M12 screw-contact field-assembly plug has both a wire termination and a cable entry. Check the selected configuration’s drawing for each. The PG7 designation alone does not supply a conductor size or the complete cable-clamping range.

When preparing a cable-and-connector specification, carry over the cable part number, conductor size and construction, insulated core diameter where relevant, and overall cable diameter with tolerance. This lets the two interfaces be checked against the same actual cable. Renhotec’s drawing and catalog downloads provide a starting point for identifying the selected product.

A wire-size conversion cannot determine how much current an assembly may carry. Conductor material, insulation temperature rating, ambient temperature, grouping and installation conditions all matter. The connector’s rating and the applicable wiring rules also need to be satisfied.

For a longer cable, check voltage drop using the specified conductor resistance and circuit length. A wire that meets a thermal requirement may still produce too much voltage drop for the load. Conversely, a larger conductor may fall outside a contact’s permitted termination range.

Use this page to translate the size and identify the measurement. Use the selected wire and connector documentation to establish the permitted assembly.