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124 LearnersLast updated on September 2, 2025

Calculators are reliable tools for solving simple mathematical problems and advanced calculations like trigonometry. Whether you’re cooking, tracking BMI, or planning a construction project, calculators will make your life easy. In this topic, we are going to talk about the area of sector calculators.
An area of sector calculator is a tool to determine the area of a sector in a circle. A sector is a part of a circle bounded by two radii and the arc between them. This calculator makes the calculation much easier and faster, saving time and effort.
Given below is a step-by-step process on how to use the calculator:
Step 1: Enter the radius: Input the radius of the circle into the given field.
Step 2: Enter the angle: Input the central angle of the sector in degrees.
Step 3: Click on calculate: Click on the calculate button to get the area of the sector.
Step 4: View the result: The calculator will display the result instantly.
To calculate the area of a sector, there is a simple formula that the calculator uses.
The formula is: Area of Sector = (θ/360) × π × r² where θ is the central angle in degrees and r is the radius of the circle.
This formula takes a fraction of the circle's area (πr²) based on the angle θ, which represents the sector's portion of the full circle.
When we use an area of sector calculator, there are a few tips and tricks that we can use to make it a bit easier and avoid silly mistakes:
Ensure the angle is in degrees. If it's in radians, convert it to degrees first.
Double-check your radius input; a mistake here can significantly affect the result.
Remember that a sector's area is always part of the total circle's area.
We may think that using a calculator prevents mistakes, but errors can still occur. Here are common mistakes and how to avoid them:
What is the area of a sector with a radius of 10 cm and a central angle of 45 degrees?
Use the formula:
Area of Sector = (θ/360) × π × r²
Area of Sector = (45/360) × π × 10² ≈ 7.85 cm²
So, the area of the sector is approximately 7.85 cm².
By substituting the values into the formula, we calculate the area of the sector as approximately 7.85 cm².
Find the area of a sector with a 15-degree angle in a circle with a radius of 20 cm.
Use the formula:
Area of Sector = (θ/360) × π × r²
Area of Sector = (15/360) × π × 20² ≈ 52.36 cm²
Therefore, the area is approximately 52.36 cm².
The formula calculates the area by considering the 15-degree angle representing a fraction of the entire circle.
Calculate the area of a sector with a radius of 8 meters and an angle of 90 degrees.
Use the formula:
Area of Sector = (θ/360) × π × r²
Area of Sector = (90/360) × π × 8² ≈ 50.27 m²
Therefore, the area of the sector is approximately 50.27 m².
The 90-degree angle is a quarter of the circle, so the area is a quarter of the circle's total area.
Determine the area of a sector in a circle with a radius of 5 inches and a central angle of 120 degrees.
Use the formula:
Area of Sector = (θ/360) × π × r²
Area of Sector = (120/360) × π × 5² ≈ 26.18 in²
Thus, the area of the sector is approximately 26.18 in².
The 120-degree central angle covers one-third of the circle, so the area is one-third of the total.
If a sector of a circle has a radius of 12 meters and a central angle of 200 degrees, what is its area?
Use the formula:
Area of Sector = (θ/360) × π × r²
Area of Sector = (200/360) × π × 12² ≈ 251.33 m²
Hence, the area is approximately 251.33 m².
The 200-degree angle accounts for more than half the circle, impacting the area proportionately.
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






