# Via Inductance

Via inductance is calculated as:
$L\text{\hspace{0.17em}}\approx \text{\hspace{0.17em}}2h\text{\hspace{0.17em}}\left[\mathrm{ln}\left(\frac{4h}{d}\right)\text{\hspace{0.17em}}+\text{\hspace{0.17em}}1\right]\text{\hspace{0.17em}}nH$
Where,
$L$
Inductance of the via [nH]
$H$
Length of via [cm]
$d$
Diameter of via [cm]

Consider a power supply pin of a component that goes through a via to the power plane of a 0.157 cm thickness board, the diameter of the via is 0.041 cm:

L = 2(0.157){ln(4(0.157)/0.041)+1} = 1.2nH