How to Calculate Diameter From Circumference

••• puflic_senior/iStock/GettyImages

A circle is a geometric form of which every point on the outside of the circle is the same distance away from the center. The distance around the edge of the circle is called the circumference. The distance from one side of the circle to the other, going through the center of the circle, is the diameter. The constant pi, designated by the Greek letter π, is the ratio of the circumference to the diameter of a circle. For any circle, if you divide the circumference by the diameter you get pi, an irregular number usually rounded to 3.14.

Setting Up the Formula

    Write down the formula for calculating the circumference of a circle;

    C = πd

    where ​C​ = circumference, π = 3.14 and ​d​ = diameter. Say aloud the meaning of the formula's symbols to make sure you understand, saying "Circumference equals pi times the diameter of a circle."

    Plug the numerical value for your circle's circumference into the formula; for instance, 12 inches. You should replace the symbol ​C​ with the measurement of your circle's circumference. In this example, write

    12 = 3.14 × d

    or "Twelve equals 3.14 times the diameter." Here, the parentheses denote the multiplication function.

    Solve the equation for the diameter of the circle,

    d= \frac{C}{π}

    In this example,

    d = \frac{12}{3.14}

    or "The diameter is equal to twelve divided by 3.14."

    Divide the circumference by pi to get the answer. In this case, the diameter would be 3.82 inches.

Related Articles

How to Find the Volume of a Sphere in Terms of Pi
How to Calculate the Diameter of a Circle From a Linear...
How to Calculate Volume of a Circular Cylinder
Characteristics of Aquatic Plants
How to Calculate Circumference in Inches
How to Calculate Volume
How to Calculate a Circular Area
How to Convert Diameter to Square Centimeters
How to Find the Height of a Rectangular Pyramid
How to Determine the Diameter of a Circle
How to Calculate Diameter to Square Feet
How to Figure the Cubic Yards in a Circle
How to Find the Perimeter of a Circle
Test Your Knowledge on Middle School Science
How to Convert Pounds Per Square Foot to PSI
How to Calculate the Radius From the Circumference
How do I Calculate 0.1%?
How to Find the Circumference of an Octagon
How to Convert Centimeters to Square Feet
How to Calculate the Area of a Curved Surface

Dont Go!

We Have More Great Sciencing Articles!