Ore grade is a measure describing the concentration of a commodity (e.g. metal or minerals) in ore. For metals sold in oxide form (such as tungsten and uranium), the grade may describe the percentage of oxide content (WO
3 and U
2O
8 respectively).
Ore grade is used to assess the economic feasibility of a mining operation; the concentration of the commodity must be high enough so that it outweighs the cost of extracting it. The ore grade required for economic feasibility varies widely based on the value of the material being mined. The lowest grade that is feasible to mine is called a cut-off grade and is determined using various economic and political considerations.