PCB Inductance Per Unit Length Formula

Equation for calculate pcb inductance per unit length is,

z = 87 / √(e + 1.41) × LN((5.98 x h) / (0.8 x w + t))
c = (2.64 x 10^-11) x (e + 1.41) / (LN((5.98 x h) / (0.8 x w + t)))
l = c x z²

z = Characteristic Impedance
e = Relative Permittivity
h = Height of Dielectric
w = Width of Trace
t = Trace Thickness
c = Capacitance per unit length
l = Inductance per unit length