For multiple cables twisted or bound together, a combined diameter circumscribing all cables can be calculated. The resulting value is also approximatively correct for three loose cables in touching trefoil formation.

Symbol
$D_{\mathrm{eq}}$
Unit
mm
Formulae
$D_{\mathrm{e}}$$N_{\mathrm{c}} \leq 1$
$1.65 D_{\mathrm{e}}$$N_{\mathrm{c}} \leq 2$
$2.15 D_{\mathrm{e}}$$N_{\mathrm{c}} \leq 3$
$2.5 D_{\mathrm{e}}$$N_{\mathrm{c}} \leq 4$
Related
$D_{\mathrm{e}}$
$N_{\mathrm{c}}$
Used in
$T_{\mathrm{4i}}$