  We employ a simple and accurate dimensional interpolation formula for the
shapes of random walks at $D=3$ and $D=2$ based on the analytically known
solutions at both limits $D=\infty$ and $D=1$. The results obtained for the
radii of gyration of an arbitrary shaped object are about $2\%$ error compared
with accurate numerical results at $D = 3$ and $D = 2$. We also calculated the
asphericity for a three-dimensional random walk using the dimensional
interpolation formula. Result agrees very well with the numerically simulated
result. The method is general and can be used to estimate other properties of
random walks.
