For single-strand cable use the following formula to calculate the exact area of the cable where the diameter of the cable-strand is known:
s = π(D/2)2
Where:
As an example, let's consider a single-strand cable with a wire diameter of 0.9mm. Applying the above formula we get:
The following formula can be used to calculate the approximate area of a multi-strand cable where both the diameter of an individual strand and the strand-count are known:
s = (πd2 / 4 (to get the area of a single strand) S = n.s (to get the approximate area of a number of strands)
Where:
As an example, let's assume we want to know the area for a copper conductor cable having 41 strands of 0.20mm wire.
First we need to calculate the area of a single strand:
0.20 × 0.20 = 0.04
0.04 × 3.14 = 0.1256
0.1256 / 4 = 0.0314
The approximate area for 41 strands is:
41 × 0.0314 = 1.2874