Last updated on August 5th, 2025
The perimeter of a shape is the total length of its boundary. However, for a sphere, the term "perimeter" is not typically used; instead, we refer to its "circumference." This is the distance around the sphere's equator. In this topic, we will learn about the circumference of a sphere.
For a sphere, we typically use the term "circumference" rather than "perimeter." The circumference of a sphere is the distance around its equator. The formula for the circumference of a sphere is 𝐶 = 2πr, where r is the radius of the sphere. For instance, if a sphere has a radius of r = 5, then its circumference is C = 2π(5) = 10π.
Let’s consider another example of a sphere with a radius of r = 7. So the circumference of the sphere will be: 𝐶 = 2πr = 2π(7) = 14π.
To find the circumference of a sphere, we just need to apply the given formula and multiply the radius by 2π. For instance, if a given sphere has a radius of r = 9, then Circumference = 2πr = 2π(9) = 18π. Example Problem on Circumference of Sphere - For finding the circumference of a sphere, we use the formula, 𝐶 = 2πr. For example, let’s say, a sphere has a radius of r = 4 cm. Now, Circumference = 2π(4) = 8π cm. Therefore, the circumference of the sphere is 8π cm.
Learning some tips and tricks makes it easier to calculate the circumference of spheres. Here are some tips and tricks given below: Always remember that the circumference of a sphere is simply 2π times the radius of the sphere. For that, use the formula, 𝐶 = 2πr. Calculating the circumference of a sphere starts by determining the radius. If you know the diameter, the radius is half of it. The formula then becomes C = πd if you prefer to use the diameter. When dealing with multiple spheres, arrange the given radii if you need the circumference for a group of spheres. After that, apply the formula to each sphere. To avoid mistakes, make sure the radius measurements are precise and consistent for common uses like manufacturing and engineering. If you are given the diameter instead of the radius, you can divide it by 2 to find the radius and then use 𝐶 = 2πr for the circumference.
Did you know that while working with the circumference of a sphere, people might encounter some errors or difficulties? We have many solutions to resolve these problems. Here are some given below:
A spherical balloon has a circumference of 62.8 inches. Find the radius of the balloon.
The radius of the balloon is 10 inches.
Let ‘r’ be the radius of the sphere. And the given circumference = 62.8 inches. Circumference of a sphere = 2πr. 62.8 = 2πr r = 62.8 / (2π) r ≈ 10 Therefore, the radius of the balloon is approximately 10 inches.
A circular track with a circumference of 100 meters is wrapped around a sphere. Find the radius of the sphere.
The radius of the sphere is approximately 15.92 meters.
Given that the circumference of the sphere is 100 meters, here is the solution: Circumference of a sphere = 2πr 100 = 2πr r = 100 / (2π) r ≈ 15.92 Therefore, the radius of the sphere is approximately 15.92 meters.
Find the circumference of a sphere with a radius of 6 cm.
12π cm
Circumference of sphere = 2πr C = 2π(6) = 12π Therefore, the circumference of the sphere is 12π cm.
A giant inflatable globe is created for a science fair. It has a radius of 3 meters. How much material is needed to wrap around the equator of the globe?
18.85 meters of material is needed to wrap around the equator of the globe.
The circumference of a sphere is the distance around its equator. Using the formula: C = 2πr C = 2π(3) ≈ 18.85 meters.
Find the circumference of a sphere with a diameter of 16 meters.
16π meters
If given the diameter, use the formula C = πd. C = π(16) = 16π Therefore, the circumference of the sphere is 16π meters.
Circumference: The total distance around a sphere, equivalent to its equator. Sphere: A three-dimensional round shape, every point on its surface is equidistant from its center. Radius: The distance from the center of a sphere to any point on its surface. Diameter: The distance across a sphere through its center, equal to twice the radius. Pi (π): A mathematical constant approximately equal to 3.14159, used in calculating the circumference and area of circles and spheres.
Seyed Ali Fathima S a math expert with nearly 5 years of experience as a math teacher. From an engineer to a math teacher, shows her passion for math and teaching. She is a calculator queen, who loves tables and she turns tables to puzzles and songs.
: She has songs for each table which helps her to remember the tables