Percentage Calculator % of a number, what percent X is of Y, and % change. Percentage Change Calculator Percentage increase or decrease between two values. Fraction Calculator Fraction arithmetic with simplified, step-by-step results. Ratio Calculator Simplify ratios and solve A:B = C:D proportions. Average Calculator Mean, median, mode and range of any number list. Standard Deviation Calculator Sample/population standard deviation and variance. Quadratic Equation Solver Roots of ax²+bx+c=0 with discriminant and steps. GCF & LCM Calculator GCF/HCF and LCM of two or more numbers. Random Number Generator Random numbers in any range, with no-repeat option.