Hildreth (2007) lists Belknap Crater's summit elevation at . McArthur and McArthur (1984) list its elevation at , while according to the U.S. National Geodetic Survey, Belknap reaches an elevation of , and has a bald appearance. The central Belknap shield volcano has a diameter of and a volume of ,[a] with a maximum thickness of . The shield has proximal and draping reliefs of and , which are the difference between summit elevation and that of highest exposure of older rocks overlain by the edifice and the difference between summit elevation and that of lowest distal lavas of the edifice (not including distal pyroclastic or debris flows), respectively. According to Hildreth (2007), Belknap Crater is a broad, low-angled shield volcano compared to other mafic (rich in magnesium and iron) volcanic cones. Belknap's summit cone rises about above the base shield volcano, and the volcano itself rises about above its surroundings.