Circumference to Diameter Calculator

Diameter and circumference are lengths related to each other — the higher the diameter, the higher the circumference. The circumference to diameter formula connects these variables in a single equation:

d = c/π

where:

• d stands for the diameter;
• c stands for the circumference; and
• π is the pi number.

If, on the other side, you're interested in how to calculate circumference from the diameter, you can solve for c in the above equation:

c = π × d

💡 Did you know?
As you can imagine from the above equations, the number π is a constant equal to the circumference-to-diameter ratio of a circle (π = c/d). If you divide the circumference by the diameter, independently of the size, it'll always be 3.14159265...

Let's look at an example. Suppose you want to find the circumference of a 5 cm diameter circle. These would be the steps to follow:

1. Use the appropriate equation, which, in this case, is the circumference to diameter formula:

   c = πd

2. Input the diameter in the equation:

   c = π × (5 cm) = 15.708 cm

3. That's it. Also, check your results using our circumference to diameter calculator. Input 5 cm in the diameter box. Your result should also be 15.708 cm.

Now that you know how to find circumference from diameter and vice-versa, you can look at other tools related to circle calculations.

• Circle calc: find c, d, a, r;
• Circle measurements calculator;
• Circle formula calculator;
• Radius of a circle calculator;
• Circle length calculator;
• Circumference and area of a circle calculator;
• Diameter of a circle calculator;
• Circle perimeter calculator;
• Square footage of a circle calculator; and
• Square inches of a circle calculator.