While looking at a circular surface, do you know how to find diameter? There are many parts of a circle such as a radius, circumference, chords, arcs, secant, tangent, sectors, and segments. The diameter is also an important part of the circle. It is a line segment passing through the center of a circle and its endpoints on the circle. In today’s post, I will show you how to find the diameter of a circle. You can easily find the value of D (diameter) using different formulas. Without wasting one more minute, let us now check out how to find diameter in detail.

**Contents**

**How To Find Diameter****?**

Using the following different ways, you can easily learn how to find diameter.

- By Using Radius
- By Using Circumference
- By Using Area
- By Using A Ruler

Generally, the distance of diameter is measured from one end of the circle to a point on the other end of the circle. It passes through the center of the circle and is denoted by the letter D. Calculating the diameter of a circle is very easy if you know either the radius (r), circumference (C), or area (A). You can also find the diameter by using a ruler.

You can keep on reading further to know more about how to find the diameter of a circle.

**Find Diameter By Using Radius**

We can easily derive the diameter from the radius of the circle. Follow these steps if you want to learn how to find diameter with radius.

- First, note down the radius of the circle.
- Recall the diameter of the circle formula;
**D = 2 x radius**. - Now, substitute the value of the radius in this formula.
- Finally, multiply the radius by 2 to get the diameter.

Always remember the diameter is twice the length of the radius.

You can keep on reading to know how to find diameter from circumference without radius.

**Find Diameter By Using Circumference**

The distance around a circle is defined as the circumference of the circle. If the circumference of a circle is known, you can easily get the value of D. You can follow these steps to learn how to find the diameter from circumference.

- First, note down the circumference of the circle.
- Recall the diameter of the circle formula; D = Circumference/ π.
- Here, π (Pi) is the constant.
- Substitute the value of circumference in this formula.
- Then, divide the circumference by π (3.141).

After completing the calculation, the final answer you get is the diameter of the circle.

**Note:** You can use the same formula if you want to know how to calculate the circumference of a circle.

**Find Diameter By Using Area**

The space occupied by the circle in a two-dimensional plane is defined as the area of a circle. You can follow these steps to know how to find the diameter from the area.

- First, note down the area of the circle.
- Recall the area of a circle formula; A = π (radius)².
- Let us modify this formula a bit; Radius = √A/ π.
- Substitute the value of Area (A) in this formula.
- Then, divide the area by π (3.141).
- Next, take the square root of the calculated value.
- Now, you will get the radius of the circle.
- Finally, multiply the radius by 2 to get the diameter.

However, you can also modify the area of a circle formula in this way: D = 2√A/ π.

**Note:** When it comes to how to find an area of a circle with diameter, you can use the same formula D = 2√A/ π.

**Find Diameter By Using A Ruler**

Sometimes, the radius, circumference, or area of a circle is not given. Do not worry, you can still find the diameter by using a ruler. Follow these steps to learn how to calculate diameter from length.

- First, draw a line passing through the center of the circle.
- Then, name the first point A and the second point B.
- This line crossing through points A and B is the diameter of the circle.
- Place your ruler on point A of this line.
- Now, start measuring the line from point A to B.

While measuring the length, make sure you use the centimeter side of the ruler (0) to get an accurate value.

**Find Diameter Of A Cylinder**

Now, you must be wondering how to find diameter of a cylinder. A cylinder has two bases, one at the top and one at the bottom. If the radius of the cylinder is given, you can easily calculate the diameter by the formula D = 2 x radius.

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**FAQ**

**How Do I Calculate The Diameter From The Circumference?**

How do I get diameter from circumference? Divide the circumference value by the number pi (π), or use the formula d = c/π .\

**What Is A Diameter In Radius?**

The distance between the center of the circle to its circumference is the radius. The diameter is always double the radius. Hence, the formula is derived by dividing the diameter by 2.

**Is Diameter Half The Circumference?**

Circumference is the length of one complete ‘lap’ around a circle, and diameter is the length of the line segment that cuts a circle in half. Think of circumference as an outer measurement and diameter as an inner measurement of the circle!

**How Do You Find The Diameter Without The Radius?**

If the circumference of the circle is 10 cm, then the diameter is 10 cm/π, or 3.18 cm. If you know the area of the circle, divide the result by π and find its square root to get the radius; then multiply by 2 to get the diameter.

**Conclusion**

In the above post, I’ve discussed how to find diameter of a circular surface. A circle can have an infinite number of diameters and each diameter is of equal length. You can easily find the value of D when the radius “r”, circumference “c”, and area “A” is given. One of the easiest ways to calculate the value of diameter is using the diameter of a circle formula i.e. D = 2 x radius. However, you can even calculate the diameter using D = Circumference/ π and Area A = π (radius)² formulas. Once you know how to find diameter, you can easily solve simple maths calculations!