Home Calculators Tools Games Circle Solver Can't remember the formulas for the other two parts of a circle (area, diameter, or circumference) when you only know one? Enter the circle area, diameter, or circumference and it will solve for the other two! Area Diameter Circumference Savings Calculator This one takes a lump sum of money and compounds it monthly over a fixed period of time at a fixed annual yield. Plus it allows you to add monthly contributions. Years Percent Yield Initial Balance Monthly Contribution   Final Balance Quadratic Equation Enter the coefficients for the Ax2 + Bx + C = 0 equation and Quadratic Equation will output the solutions (if they are not imaginary). A = B = C = X1 = X2 = Prime Number Enter a number and the Prime Number Calculator will instantly tell you if it is a prime number or not. Enter a number