Last updated: Aug 29, 2024

Circumference to Diameter Calculator

Q: What is the circumference of a 6-foot diameter circle?

18.8496 feet . To convert diameter to circumference : Take the diameter . Multiply it by the number pi (π) . In this case, the circumference equals: π × 6 ft = 18.8496 ft .

Q: How do I get diameter from circumference?

Divide the circumference value by the number pi (π), or use the formula d = c/π . That's how you find the diameter of a circle with its circumference.

Created by Luis Hoyos

Luis Hoyos

Luis Hoyos is a fresh graduate Mechanical Engineer with thermodynamics and fluids mechanics expertise. He's interested in learning new things and applying them to real-life problems. Luis also likes to build tools that make repetitive and boring tasks a breeze, like calculators (surprise?). When he's not creating calculators, he's in the process of building the size of the tissue attached to his bones, aka bodybuilding. He also loves being with his little cat and seeing her do crazy things. See full profile

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Reviewed by Wojciech Sas, PhD

Wojciech Sas

PhD, Institute of Physics in Zagreb

A physicist at the Institute of Nuclear Physics in Kraków. Currently looking for that one and only magnetic nanomaterial that will improve everyone's life. Interested in astronomy and likes playing board games. Also, fond of watching chess tournaments; he never refuses to play a game (or two) himself. See full profile

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Table of contents

The circumference to diameter formula How to find circumference from diameter: an example Other-circle related tools FAQs

The circumference to diameter calculator can help you solve the geometry problem of finding the diameter of a circle by inputting its circumference. This calculator works both ways, so you can also convert a diameter to a circumference.

Keep reading to learn more about:

The circumference to diameter formula.
How to calculate circumference from the diameter.
How to get diameter from the circumference.

The circumference to diameter formula

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...

How to find circumference from diameter: an example

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:

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

c = πd
Input the diameter in the equation:

c = π × (5 cm) = 15.708 cm
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.

FAQs

What is the circumference of a 6-foot diameter circle?

18.8496 feet. To convert diameter to circumference:

Take the diameter.
Multiply it by the number pi (π).
In this case, the circumference equals: π × 6 ft = 18.8496 ft.

How do I get diameter from circumference?

Divide the circumference value by the number pi (π), or use the formula d = c/π. That's how you find the diameter of a circle with its circumference.