Depends a lot on the weave. Midweight Smartwool in size medium goes 7.7 ounces for tights, 8.1 ounces for the tops. Some heavier tops like the Ibex Shak half zip goes 14.1 ounces. The lightest I have is an Ibex Woollies crew at 5.8 ounces and a short sleeved Smartwool Micro T at 4.5 ounces.