Marks percentage calculator

When every paper shares one maximum, the aggregate and the average of subject percentages are the same number. When maxima differ they are not: totaling the marks then dividing by the total maximum is the honest figure, and averaging the per-paper percentages quietly weights a 10-mark paper the same as an 80-mark paper, so both are shown here. Divisions and letter grades are conventions, and the CGPA conversion is a linear formula with published constants, not a definition; both factors are editable for boards that disagree with CBSE's 9.5.