Home Mathematics Area. We can see this on the graphic below. Circle Area Circumference Diameter Calculator Circle Formula Circle Circumference The area of a circle calculator helps you compute the surface of a circle given a diameter or radiusOur tool works both ways - no matter if youre looking for an area to radius calculator or a radius to the area one youve found the right place. . Calculates the radius diameter and circumference of a circle given the area. The circumference of a circle is calculated with the help of the circumference formula that needs the value of the radius of the circle and the value of π pi. Dimensions of a Circle. Sphere surface area to radius calculator. Well give you a tour of the most essential pieces of information regarding the area of a circle its diameter and its radius. Enter the circumference which is the total length of the edge around the circle if it was straightened out.