According to Planck:
$E=hv$
$h=\frac{E}{v}$
Substituting the dimensions of known physical quantities:
$\begin{array}{l}\left[h\right]=\frac{\left[M{L}^2{T}^{-2}\right]}{\left[T^{-1}\right]}\\ \mathrm{or}\left[h\right]=M{L}^2{T}^{-1}\end{array}$
So, SI unit or Planck’s constant is kg m²s^–1 which can also be written as
$\left(kg{m}^2{s}^{-2}\right)\times s$ . But as  $kg{m}^2{s}^{-2}$ is joule, so unit of h is  $joule\times \sec$ , i.e., Js.