Any impulse results in the formation of a solitary wave of time averaged width W in a granular chain. If the grain-grain interaction potential V∼ δn, where δ is the distance by which the grains approach each other, then it is well established that n≥ 2. Here we present dynamical simulation based results which suggest that W-1 ∝ (n-2)-α where α =0.3283 or ≈ 1/3. While in qualitative agreement, the result is quantitatively different from the formula for W proposed earlier by Nesterenko. © 2013 Springer-Verlag Berlin Heidelberg.