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**Education Calculators** ▶ Circumference Calculator

An online circumference calculator that allows you to find circumference, radius, diameter, area, sphere surface area, and sphere volume of a circle. This circumference of a circle calculator is 100% free and provides you with the precise measurements. Well, in this stuff, the team of calculator-online decided to provide you the better understanding about how to find the area and circumference of a circle, and much more that you need to know! But, before knowing these all terms, you should beware about some key-points about this calculator for circumference and right after lets we begin with some basics!

This calculator is specifically best to perform calculations between:

- Circumference to diameter
- diameter to circumference
- circumference to radius
- radius to circumference
- circumference to area
- area to circumference
- radius to diameter
- diameter to radius
- radius to area
- area to radius
- diameter to area
- area to diameter

Well, it doesn’t matter at all whether you want to convert circumference to diameter or radius to diameter, this tool will assists you to find these all above parameters for circle.

Now, it’s time to begin with some basics definitions, so first of all we are going to elaborate the definition of the circumference of a circle, swipe down!

Also, this online geometry calculator by calculator-online works best to determine the coordinates of the midpoint with the x & y coordinates.

The circumference is an important property of circle; it is referring as the distance around the outside of the circle. In simple words, it is the linear distance of a circle’s edge. The circumference is similar to the perimeter of a geometric figure but remembers that ‘perimeter’ is the term that is only used for polygons.

Circumference of a circle is simply evaluated by multiplying radius of the circle with 2 and π. Well, the formula for circumference can be stated as:

- C = 2πr

In this circumference equation:

- C represents the “circumference of a circle”
- r is said to be as the “radius of the circle
- π is said to be as the ratio of a circle’s circumference to its diameter, it is mathematical constant that approximately equals to “3.14159”

If you don’t love math, then simply add the values into the above given circumference formula calculator to calculate circumference directly as it also uses the same equation for circumference.

A radius of circle is referred to as a straight line from the center of a circle to the circumference of a circle. And, if you have two or more of them, they’re said to be as radii. The plural for is radii that is pronounced as “ray-dee-eye” and remember that all radii in a circle will be the same length.

Also, sometimes the word “radius” is considered to indicate to the line itself. In contrast of that sense you may see “draw a radius of the circle”. For further detailed query, it is said to be the length of the line, and so it is referred to as the “radius of a circle that is 1.7 cm.”

And, an online radius of a circle calculator is the tool that assists you to find the radius for the given circle within a couple of seconds.

There are different formulas for radius that helps in finding the radius of the circle, these are:

**If the diameter is given:**

radius = D/2

Where;

- D is said to be as the diameter of the circle

**If the circumference is given:**

radius = C / 2π

Where;

- C is said to be as the circumference of the circle
- π is refers to as the Pi that is approximately 3.142

**If the area is given:**

radius = √ A / π

Where;

- A is said to be as the area of the circle
- π (Pi) = approximately 3.142

The diameters of a circle the measurement referred to as the length of the line through the center and touching two points on its edge. The diameter is something that measures how big the circle is from rim to rim passing through the center.

Some certain times the word “diameter” is utilized to indicate the line itself. In that sense, you may notice “draw a diameter of the circle”. More specifically, it is said to be as the length of the line, and indicated as the “diameter of the circle that is 3.4 centimeters”. The diameter is also said to be as a chord.

There are different formulas for calculating diameter of the circle:

**If the radius is given:**

Diameter = 2R

Where;

- R is said to be as the radius of the circle

**If the circumference is given:**

Diameter = C / π

Where;

- C is indicated as the circumference of circle
- π is Pi that is approximately 3.142

**If the area is given:**

Diameter = √4A / π

Where:

- A is referred to as the area of the circle
- π is said to be as a Pi, which is approximately 3.142

Apart from these formulas, you simply add the value into the designated filed of the diameter of a circle calculator to find the diameter of the circle instantly.

The area of a circle is referred to as the number of square units inside that circle. Remember that if each square in the circle to the left has an area of 1 cm^2, then you could simply count the total number of squares to get the area of this circle.

The area of a circle calculator by calculator-online is also uses the same formula to find the area of a circle.

Area of a Circle, A = πr^2 square units

Where;

- π is said to be pi that is equal to 22/7 or 3.14
- r is the radius

You can readily work out for the centroid of any N-Points, N-sided Polygon, and triangle with this help of this free calculator by calculator-online.

The surface area of a sphere is refers to exactly four times the area of a circle with the same radius. For a better understanding, you can look at the given formula of surface area of a sphere.

4πr^2

A sphere is referred to as a set of points in space that are a given distance r from the center. And, the volume that enclosed by a sphere is given by the mentioned formula.

V = 4/3 πr^3

Where;

- π = 22/7 or 3.14
- r is radius

The simple, but highly accurate circle circumference calculator that helps you in finding the circumference, radius, diameter, area, surface area of a sphere, and sphere volume of a circle. This calculator is quite easy to use and provides you the precise measurements within a couple of seconds. The circumference of a circle calculator not only calculate circumference accurately, but also the other parameters that mentioned above.

This calculator for circle circumference is packed with simple & user-friendly interface through which you can easily find the circumference, area, and different other parameters of circle.

**Inputs:**

There are 6 different input fields that provided by this calculator:

- Radius (R)
- Diameter (D)
- Circumference (C)
- Area (A)
- Sphere Surface Area
- Sphere Volume

All you need to enter one of these known parameters to find the remaining five values. Just enter any single value and hit the calculate button.

**Outputs:**

Once done, this circumference of a circle calculator will generate:

- Radius (R)
- Diameter (D)
- Circumference (C)
- Area (A)
- Sphere Surface Area
- Sphere Volume
- Also, this calculator shows you the formula for each parameters that uses by our calculator to provides you the precise measurements

The values for each parameter are different as it depends on the given value.

Area of any circle can be calculated with the help of formula or circle area calculator. Different formulas will be applied in different conditions. Situation might be:

- Area of the circle can be calculated by π r square.
- If you know the diameter of the circle, then the formula will be: (π/4) × D square.
- If the circumference of the circle is known, then the formula will be: A = C square / 4π.

**Example:**

What will be the possible area of a circle if its radius is 3?

- As the diameter is present so the formula will be: π r square.
- Value of π (pi) is fixed that is: 3.14
- Whereas r = 3
- Radius will be equal to 9 after taking its square so new value of r = 9
- Radius will be multiplied by value of pi = 28.27 m square.
- Area of a circle = 28.27 m square.

Circumference is the distance that is present around the circle and can be calculated by applying a simple formula that is: π (multiplied by) d or 2πr.

- In the above formula d is representing radius of the circle.

**Example:**

If diameter of any circle is 18 then what will be its circumference?

- We will apply formula for circumference and simply put the values in it as follows:
- Value of pi 3.14 and value of d is 18. Therefore, on multiplication we will get circumference of a circle = 56. 5 inches.
- We measure circumference in inches.

Also, our circumference of a circle calculator follows the same way for finding the circumference of a circle.

Distance from the midpoint to the edge of the circle represents its radius and can be measure simply by applying its formula that is: r = C / 2 x 3.14

- R is radius
- C represents circumference
- 3.14 is the value of pi

**Example:**

If the circumference of any circle is 4 then what will be its radius?

- C = 4
- Pi = 3.14
- R = c / 2 x 3.14 = 4 / 2 x 3.14 = 0.63 cm

Diameter divides the circle in 2 equal halves and can be calculated by means of simple formula that is: 2r.

- Whereas r represents the radius of the circle.

**Example:**

If the radius of the circle is 2 then what will be its diameter?

- We will apply the formula to calculate diameter and put the values in it as follows:
- Diameter = 2 multiplied by 2 = 4 cm.

Surface area of a sphere can be calculated by applying formula: 4 x 3.14 x radius of the circle. To calculate it all we have to do is to put the values in this formula. It is represented by A.

**Example:**

If the radius is 5 then what will be surface area of the sphere?

- Sphere surface area = 4 x 3.14 x r square = 314.159 cm²

Sphere volume can be calculated by the formula: 4 / 3 (3.14 multiplied by r cube). While doing calculations we will put value of radius and multiply it 3 times. after that, we will do calculations according to the formula.

Example:

If the radius is 2 then what will be sphere volume?

- R = 2
- On taking cube of radius = 8
- Therefore sphere volume= 4 / 3 (3.14 x ) = 33.51029 cm³

Wondering to know how big the earth is, you are at the right spot! Well, all you need to use pi (π) to find the circumference of the Earth! Since scientists already depicted that the diameter of the Earth is 12,742km. So, get the paper and pencil to work out the circumference of the earth.

So,

- C = πd
- Diameter of the earth is 12,742km
- So, all you need to add the values into the above equation for circumference to calculate the circumference of the earth
- C = π x 12,742km = 40,030km
- So, the circumference of the earth is 40,030km.

Also, the online circumference calculator helps you in calculating circumference for earth directly.

Simply, add the values into the above circumference to diameter calculator to find the diameter from the given circumference. And, for manual calculation, read on!

As you know that circumference and diameter are the two measurements that are related by π, so, we can use π (Pi) to find the diameter from circumference. All you need to stick to some basic math:

- C = πd
- C/π = d
- Simply, dividing the circumference by π (Pi), then you will get the diameter!

**For example:**

So, how to find diameter from circumference, let’s take a look at the below-mentioned example:

A circle has 15 feet circumference, so, what’s its diameters?

So,

- C = πd
- C/π = d
- Add the circumference value into the formula:
- 15 feet / 3.14159 = d
- 4.77466 feet = d

The above diameter to circumference calculator will directly turn values from diameter to the equivalent circumference value. And, if you want to do it yourself, then swipe down!

Circumference is related to diameter, so all you need to use that ratio to a missing parameter. Suppose that you need to find circumference from diameter. So, here we can write the relationship as:

- C/d = π
- C = π x d
- C = πd

So, how do you find the circumference from diameter, take a look at the given example:

**For example:**

The circle is with 20 cm diameter, so what’s it circumference!

So,

- C = πd
- Add the values into the above equation:
- C = 3.14159 (20 cm)
- C = 62.8318

The diameter of a 14 inch circumference is equal to 4.45634 inches.

You can readily find the circumference of a 15 ft circle with the given formula:

- C = πd
- Add the values
- C = 3.14159 (15 ft)
- C = 47.12 ft

The circumference of a 30 cm circle is equal to 94.2478 cm.

The distance around the edge of the circle is said to be as the circumference of a circle. While, the distance from one side of the circle to other, which going through the center of the circle is referred to as the diameter.

The circumference of 14ft of a circle is equal to 43.9823 ft.

The diameter of a 4 inch circumference is 1.27324 inch.

The radius of a 20 foot circle is equal to 10 ft.

The circumference of a circle is refers three times to its diameter approximately.

- First of all, you need to measure the diameter of the pipe. For instance, let’s suppose that the pipe has a diameter of 4 feet
- Now, you ought to work out how accurate your measurement needs to be. If you just require a general estimate, you can account 3.14 as pi (π). If you want to attain more accurate measurement, you have to carry (π) out to more decimals. Remember that pi (π) begins at 3.14159265 and continues from there
- Very next, you just need to multiply the diameter by pi (π). In the given example, 4 ft times 3.14 equals to 12.46 ft

The circumference of a 8 foot diameter circle is equal to 25.13274 foot.

The circumference divided by diameter equal to pi as pi (π) has been originally stated as the unknown number, which was equal to the circumference (C) of a circle divided by its diameter (D). Remember that the value of pi (π) is equal to the circumference of a circle divided by its diameter.

The circumference of a 20 inch circle is equal to 62.8319 inch.

The diameter of a 72 inch circumference of a circle is equal to 22.9183 inch.

The diameter of a 5 inch circumference of a circle is equal to 1.59155 inch.

The radius of a 6 foot circle is equal to 3 ft.

All you need to plug-in the values into the circumference to radius calculator to turn from circumference to radius or radius to circumference.

The radius of a 22 ft circle is equal to 11 ft.

The radius of a 12 foot circle is equal to 6 ft.

The radius of a 100 cm circle is equal to 50 cm.

In its simplest form, the ratio of a circle circumference to its radius is 2 Pi (π) to 1. For every single unit of radius, there are 2 is 2 Pi (π) units in the circumference.

Thankfully, you come to know how to find circumference and different other parameters of the circle. Keep in mind that Circumference, diameter, and radius are something that can be measured in linear units, including inches and centimeters. However, a circle has many different diameters and many different radii that each is passing through the center. So, utilize this simple circumference calculator by calculator-online to solve the circle parameters!

From the source of Wikipedia: About Circumference – The term of circle and (relationship with π)

From the source of tutors: about Pi and Circumference/Diameter – Also, Blame Welsh mathematician William Jones used the Greek word for circumference, περιϕέρεια, (π)

From the source of khanacademy: the guide about the relationship between the radius, diameter, and circumference of the circle.

The source of calcworkshop provides with: how do I calculate the circumference of a circle (find the 13 solved examples)

From the source of scientificamerican: What Is Pi, and How Did It Originate (A simple guide)