A rotary lawn mower cutting blade with reduced drag and improved cutting ability includes a central mounting section, intermediate sections, and outboard sections along a common longitudinal axis and disposed about a common center of rotation. The outboard sections include downward and inward projecting sections. The cutting blade also preferably includes cutting edges on the full extent of the leading edge of the outboard section including the downward and inward projecting sections. Additionally, the outer section can be twisted slightly to enhance airflow upward.