What’s the difference between diameter and cross-section?
The diameter in mm is a linear measure, the crosssection in mm² is an area measure.
For solid conductors and single wires the diameter is specified in mm. For inner conductors, which consist of multiple single wires/braided wires, we quote the cross-section.
The cross-section (A) can be calculated from the diameter (d) using the following formula:
A = (d² x Pi)/4 ≈ 0.785 x d²