Many recipes call for a tomato of a certain size.  How do you know the difference between small, medium and large tomatoes? 
USDA requirements for measurements used by the Fresh Market  tomato industry                   **Size**           **Size**                 No Pass            Pass                  inches             inches                 see note #1        see note #2   Small           2 1⁄8 inches       2 9⁄32 inches Medium          2¼ inches          2 17⁄32 inches Large           2½ inches          2 25⁄32 inches Extra Large     2¾ inches       note # 1. Will not pass through a round opening with this diameter when the tomato is held with its greatest diameter parallel to the plane of the opening.  note # 2. Will pass through a round opening of this size; the tomato may be held in any position for the test. 