Diameter is the length of the line through the center that touches two points on the edge of the circle known as the circumference while radius is the distance from the center to the circumference of a circle.
Formula to calculate radius from diameter.
In other words, we can say that diameter is twice the radius or radius is half the diameter.
Example:
Calculate the radius of a circle whose diameter is 14 cm.
Therefore, the radius of the circle is 7cm.