The smallest size dumpster to rent is a 5 yard dumpster, although the smallest most companies carry is a 10 yard dumpster. The most efficient small dumpsters, with the smallest footprint are 3 feet high, 7 feet wide and 10 feet long. These efficiently built dumpsters are not boat or bathtub style with the rounded bottom. They are simply rectangular which allows for the best packing of debris. This small dumpster size is often used for heavy debris like concrete, brick, soil, rock and similar materials.