We significantly improve the physical understanding and theoretical estimate of the contact resistance of a side-bonded contact to heavily doped semiconductor nanowire by highlighting the edge effects. The contact can be made of metal or metal silicide. Prior model of a side-bonded contact to semiconductor nanowire (NW) estimates the contact resistance using radial tunneling in the contacted NW region, neglecting the edge tunneling and fringing field in the non-contacted NW region. Using realistic TCAD simulations, we show that: (i) edge tunneling dominates over radial tunneling as contact thickness, nanowire radius or ambient dielectric constant are reduced; hence a thin contact together with a low-k surrounding dielectric can yield a significantly lower contact resistance; (ii) fringing field reduces both radial tunneling and edge tunneling. © 2021 Elsevier B.V.