The following formulae can be used to calculate the approximate diameter 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 defined number of strands)
(to get the approximate diameter of a defined number of strands)
| where | s | = | area of a single strand |
| d | = | diameter of a single strand | |
| D | = | diameter of a defined number of strands | |
| π | = | 3.14 | |
| S | = | area of defined number of strands | |
| n | = | number of strands |
As an example, let's assume we want to know the approximate diameter for a multi-strand cable having 41 strands of 0.20mm wire.
First we need to calculate the area of a single strand:
0.20 x 0.20 = 0.04
0.04 × 3.14 = 0.1256
0.1256 4 = 0.0314
The approximate area for 41 strands is then found:
41 × 0.0314 = 1.2874
Now knowing the approximate area, we can get the approximate diameter by using the formula:
(4 × 1.2874)3.14 = 1.6400
= 1.2806 (1.3mm Diameter)