# Square Inches of a Circle Calculator

Created by Wei Bin Loo
Reviewed by Dominika Śmiałek, MD, PhD candidate
Last updated: Mar 15, 2022

With this square inches of a circle calculator, you can easily calculate the area of a circle in square inches. As square inch is a widely used unit, especially in the construction industry, it is essential to understand how to find the square inches of a circle.

This article will help you understand what the square inches of a circle is and how to find the square inches of circle. The article will include a practical example to help you understand this concept and its application.

## What is the square inches of a circle?

Square inches of a circle is the area of a circle converted to square inches. As square inches is an imperial unit, this is mainly used in countries such as the United States, Myanmar, and Liberia.

Although most countries nowadays use metric units, such as meters, kilometers, centimeters and so on, units like square inches are still widely used in some industries. For instance, square inches is widely used in the construction industry.

## How to find the square inches of a circle?

To understand the calculation, let's take the following circle as an example:

• Shape: circle
• Dimension: 2D
• Radius: 3 cm
• Diameter: 6 cm
1. Determine the radius of the circle

The first step is to determine the radius of the circle. The radius of the circle in our example is 3 cm.

1. Convert the radius into inches

For the next step, we need to convert the radius into inches. As the radius of the circle in our example is in cm, we need to multiply the number by 0.3937. Hence, the radius of the circle is 1.181 in.

To convert different units to inches, please refer to the table below or refer to our length converter.

Units

millimeter (mm)

centimeter (cm)

meter (m)

kilometer (km)

inch (in)

foot / feet (ft)

yard (yd)

mile (mi)

nautical mile (nmi)

1 inch (in)

25.4

2.54

0.0254

0.0000254

1

0.08333

0.02778

0.000015783

0.000013715

1. Calculate the square inches of a circle

The final step is to calculate the square inches of a circle. We can achieve this by applying the circle area formula:

area = π * radius²

Thus, the square inches of the circle is π * (1.181 in)² = 4.3825 in², which is 4.3825 square inches.

## Why should we calculate the square inches of a circle?

Now that we understand what the square inches of a circle is, we can discuss the importance of this concept. As mentioned earlier, a square inch is a unit that is widely used in the construction industry. Hence, understanding the square inches of a circle can help you to communicate better with people in the industry.

For example, if you want to buy a circle carpet, it is better to tell them how many square inches or square feet you want the carpet to be, instead of square meters or square centimeters.

Apart from our square inches of a circle calculator, you may also find some of the circle-related calculators below helpful:

## FAQ

### What is a circle?

A circle is a planar closed curve made of a set of all the points that are at a given distance from a given point - the center. The circle can also be defined as the locus of points at the same distance from a given fixed point.

### What is a radius?

A radius is a line from the centre of the circle to the edge of the circle. It is half of a diameter, which is a line stretches from an edge of a circle to another edge of the circle.

### How do I calculate the square inches of a circle?

We can calculate the square inches of a circle in three steps:

1. Determine the radius of the circle
2. Convert the radius into inches
3. Calculate the square inches of a circle
Wei Bin Loo in
Area (A)
in²
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