This paper is devoted to exploring the relationship between the [1,n)∋p-capacity and the surface-area in Rn≥2 which especially shows: if Ω⊂Rn is a convex, compact, smooth set with its interior Ω∘=∅ and the mean curvature H(∂Ω,⋅)>0 of its boundary ∂Ω then (p(n−1)n(p−1))p−1≤(σn−1area(∂Ω))n−1n−p((n−pp−1)1−pσn−1capp(Ω))≤(n−1∫∂Ω(H(∂Ω,⋅))n−1σn−1dσ(⋅))p−1∀p∈(1,n) whose limits 1←p&p→n imply 1=area(∂Ω)cap1(Ω)&∫∂Ω(H(∂Ω,⋅))n−1σn−1dσ(⋅)≥1, thereby not only discovering that the new best known constant is roughly half as far from the one conjectured by P\'olya-Szeg\"o in \cite[(2)]{P} but also extending the P\'olya-Szeg\"o inequality in \cite[(5)]{P}, with both the conjecture and the inequality being stated for the electrostatic capacity of a convex solid in R3.