Copper is a fairly common element, with an estimated concentration of 50–70 ppm (0.005–0.007 percent) in Earths crust (1 kg of copper per 15–20 tons of crustal rock). A concentration of 60 ppm would multiply out to 1.66 quadrillion tonnes over the  mass of the crust, or over 90 million years worth at the 2013 production rate of 18.3 MT per year. However, not all of it can be extracted profitably at the current level of technology and the current market value.
The USGS reported a current total reserve base of copper in potentially recoverable ores of 1.6 billion tonnes as of 2005, of which 950 million tonnes were considered economically recoverable. A 2013 global assessment identified "455 known deposits (with well-defined identified resources) that contain about 1.8 billion metric tons of copper", and predicted "a mean of 812 undiscovered deposits within the uppermost kilometer of the earth's surface" containing another 3.1 billion metric tons of copper "which represents about 180 times 2012 global copper production from all types of copper deposits."