How to Figure Percentage of a Circle Graph

A protractor helps measure angles.
••• Ableimages/Photodisc/Getty Images

A circle graph, also known as a pie chart, shows the makeup of a group of data based on the percentage of the total that each subgroup represents. For example, a circle graph might show the revenue from the four lines of business a company has in place or the amount of sales resulting from each store. Each slice of the circle graph represents a percentage. To find the percentage represented by each slice, you need to know the angle measure of the slice.

    Measure the angle of the sector of the circle graph with a protractor. Line the straight edge of the protractor up with one of the radii that form the sector and then find the angle measure from where the other radius intersects the curved edge of the protractor.

    Divide the angle measure by 360 because to find the portion of the circle represented by the sector. For example, if the sector measures 162 degrees, divide 162 by 360 to get 0.45.

    Multiply the portion by 100 to convert to a percentage. In this example, multiply 0.45 by 100 to find that a sector measuring 162 degrees equals 45 percent of the circle graph.

    Things You'll Need

    • Protractor
    • Calculator

Related Articles

How to Calculate Arc Area
How to Find the Radius of a Partial Circle
How to Calculate Volume of a Circular Cylinder
How to Find the Radius of a Sector
How to Calculate the Perimeter of Combined Shapes and...
How to Calculate Perimeter and Area Ratio
How to Calculate Diameter to Square Feet
How do I Calculate 0.1%?
How to Find Y Value for the Slope of a Line
How to Calculate the Diameter of a Circle From a Linear...
How to Find the Area of a 12-Sided Polygon
How to Calculate the Diameter of a Rectangle
How to Solve a Hexagon
How to Find the Distance Between Two Points on a Circle
How to Calculate the Linear Footage in a Radius
How to Find FWHM
How to Find the Area of a Shaded Part of a Square With...
How to Calculate the Arc Length, Central Angle, and...
How to Find a Z Score
How to Convert Diameter to Square Centimeters

Dont Go!

We Have More Great Sciencing Articles!