  We constrain the inverse moment of the $B$-meson light-cone distribution
amplitude (LCDA), $\lambda_B$ in heavy quark effective theory, using form
factor estimates from Lattice QCD collaboration. The estimation of the
parameter $\lambda_B$ has, until now, relied solely on QCD sum rule methods and
deals with significant uncertainty. In this work, we express the form factors
for the $B \to K$ channel, calculated within the light-cone sum rule (LCSR)
approach, in terms of the $B$-meson LCDAs. By incorporating recent Lattice
results from the HPQCD collaboration for the $B \to K$ form factors at zero
momentum transfer ($q^2$ = 0), we impose constraints on this parameter.
Consequently, we achieve a twofold reduction in uncertainty compared to the QCD
sum rule estimate, yielding $\lambda_B=338\pm 68$ MeV, when the $B$-meson LCDAs
are expressed in the Exponential model. Additionally, we compare the form
factor predictions, using the constrained $\lambda_B$ value, with the earlier
analyses for other channels as well, such as $B\to \pi$ and $B \to D$.
