  We develop the interface tool $\verb|wan2respack|$, which connects
$\verb|RESPACK|$ (software that derives the low-energy effective Hamiltonians
of solids) with $\verb|Wannier90|$ (software that constructs Wannier
functions). $\verb|wan2respack|$ converts the Wannier functions obtained by
$\verb|Wannier90|$ into those used in $\verb|RESPACK|$, which is then used to
derive the low-energy effective Hamiltonians of solids. In this paper, we
explain the basic usage of $\verb|wan2respack|$ and show its application to
standard compounds of correlated materials, namely, the correlated metal
SrVO$_3$ and the high-$T_{c}$ superconductor La$_2$CuO$_4$. Furthermore, we
compare the low-energy effective Hamiltonians of these compounds using Wannier
functions obtained by $\verb|Wannier90|$ and those obtained by
$\verb|RESPACK|$. We confirm that both types of Wannier functions give the same
Hamiltonians. This benchmark comparison demonstrates that $\verb|wan2respack|$
correctly converts Wannier functions in the $\verb|Wannier90|$ format into
those in the $\verb|RESPACK|$ format.
