Like all Type XXI submarines, U-2511 had a displacement of when at the surface and while submerged. She had a total length of (o/a), a beam of , and a draught of . The submarine was powered by two MAN SE supercharged six-cylinder M6V40/46KBB diesel engines each providing , two Siemens-Schuckert GU365/30 double-acting electric motors each providing , and two Siemens-Schuckert silent running GV232/28 electric motors each providing .
