[amsat-bb] Insulated AWG to bare copper or aluminum

Hello All, I am wondering if there is any "simple" conversion factor to use to modify the length of an antenna element from insulated #10 AWG copper wire to anther gage of wire or to aluminum or copper tubing.  I don't wish to learn any modeling software at this time   I need the information so I can use materials I have on hand to build yagi antennas for 2 meters and 70 centimeters.   Thanks and 73,James, AA5AO