Grades of Concrete are defined by Strength and Composition. Structural Analysis enables us in determining the Grade of Concrete to be used in construction. The Grade of concrete is defined as the minimum strength the concrete must possess after 28 days of construction with proper quality control.  According to Indian Standard codes, concrete grade generally refers to the cube test, for finding out the compressive strength of concrete on the 28th day. The grade of concrete is denoted by prefixing M with the desired strength in MPa. For example, a grade of concrete with 25 MPa strength, will be denoted by M25, where M stands for Mix. Components of Concrete include Cement, sand, aggregates and water. Different mixes (M) come in various mix proportions of the various ingredients of cement, sand and coarse aggregates. Now, have a look at the Concrete Mix Design Table