Use this engineering calculation for a transparent preliminary estimate or independent arithmetic check when geometry, materials, loads, operating conditions, and units are defined consistently.

Diameter Millimeters (mm)

Required number input.

Circular solid conductor cross-sectional area from measured diameter, excluding insulation. The tool evaluates the supplied inputs together and returns the named outputs below; it does not infer omitted operating conditions or change the units shown.^[1]

Area Square Millimeters (mm²)

The resulting area square millimeters returned as a number.

• Electrical estimates require the correct AC or DC model, RMS and phase conventions, source impedance, grounding, conductor conditions, protection, temperature, harmonics, faults, and applicable standards. Nominal ratings are not automatically compatible design limits.
• Use finite inputs in the displayed units and preserve more precision than the final presentation requires. Independently verify safety-critical, financial, compliance, or production decisions.

Check assumptions against drawings, measurements, current material data, and the applicable design code. Apply required load combinations and safety factors, then obtain qualified review and testing for consequential designs.

• Moment Inertia Circle

  Centroidal second moment of area of a solid circular section about any in-plane diameter: πd⁴/64.

• Rebar Area

  Circular reinforcing bar cross-sectional area from nominal bar diameter, not including ribs.

• AWG Diameter

  Nominal solid conductor diameter from American Wire Gauge number, using d(in)=0.005·92^((36−AWG)/39). Use -1 for 2/0, -2 for 3/0 and -3 for 4/0 AWG; zero is 1/0.