This document from April 2016 provides updates to the volume-to-weight conversion factors found in the 1997 report, "Measuring Recycling: A Guide for State and Local Governments."
You may need a PDF reader to view some of the files on this page. See EPA’s About PDF page to learn more.- Volume-to-Weight Conversion Factors for Solid Waste (PDF)(7 pp, 325 K, April 2016)