  We present an \emph{ab initio} study of the effect of macroscopic deformation
on energetics of twelve alloying elements in bcc Fe under three specially
designed strain modes. We find that there exists a universal linear relation of
describing the volume dependence of substitutional energy of alloying elements
via introducing two factors --- the system shape factor ($f_{\scriptsize{ss}}$)
and the size factor of alloying element $M$ ($\Omega^{M}_{\scriptsize{sf}}$):
$E_{\scriptsize{sub}} \sim f_{\scriptsize{ss}}\Omega^{M}_{\scriptsize{sf}}V$.
$\Omega^{M}_{\scriptsize{sf}}$ well describes the effect of intrinsic
alloying-atom size and the influence of chemical interaction with matrix atom,
and $f_{\scriptsize{ss}}$ characterizes the degree of system lattice distortion
under deformation. This relation is further validated using the published data
of stained-modulated doping in GaP
