What context can I use each word in?
Learn when and how to use these words with these examples!
radius
Example
The radius of this circle is 5 centimeters. [radius: noun]
Example
Draw a circle with a radius of 3 inches. [radius: noun]
Example
The hurricane has a radius of 100 miles. [radius: noun]
diameter
Example
The diameter of this circle is 10 centimeters. [diameter: noun]
Example
Draw a circle with a diameter of 6 inches. [diameter: noun]
Example
The swimming pool has a diameter of 30 meters. [diameter: noun]
Good things to know
Which word is more common?
Diameter is more commonly used than radius in everyday language, especially in mathematical contexts. Diameter is a fundamental measurement in geometry and is used in various fields, such as engineering, physics, and architecture. Radius is less common but still important in describing circular objects or areas.
What’s the difference in the tone of formality between radius and diameter?
Both radius and diameter are formal words used in technical or scientific contexts. However, diameter is more versatile and can be used in both formal and informal situations, while radius is less common and may sound more technical or specialized.
