Although sheets of layered van der Waals solids offer great opportunities to custom-design nanomaterial properties, their weak interlayer adhesion challenges structural stability against mechanical deformation. Here, bending-induced delamination of multilayer sheets is investigated by molecular dynamics simulations, using graphene as an archetypal van der Waals solid. The simulations show that delamination of a graphene sheet occurs when its radius of curvature decreases roughly below Rc = 5.3 nm × (number of layers)(3/2) and that, as a rule, one-third of the layers get delaminated. These clear results are explained by a general and transparent model, a useful future reference for guiding the design of nanostructured van der Waals solids.