what is the accepted range in a rdw test
RDW-CV and RDW-SD. Red blood cell distribution width is a way for scientists to measure red blood cell volume and size. When red blood cells are larger than normal, that could indicate a problem. The reference range for RDW is as follows: 1  RDW-SD: 29-46 fL. 2  RDW-CV: 11.6 â 14.6% (for adults).