radius vs diameter
The radius is the distance from the center of a circle to its edge, while the diameter stretches across the circle through its center, measuring twice the radius. Understanding both helps you easily calculate the circle’s area, circumference, and other properties.
Circle Properties
Calculation Steps
Circle Calculator Answers
How do I find the circumference using the radius?
To find the circumference when you know the radius, multiply the radius by 2 and then by π (pi). The formula is C = 2 × π × r. This gives the total distance around the circle based on the radius length.
How to Find the Diameter of a Circle?
The diameter is the longest distance across a circle, passing through its center. You can find it by doubling the radius:
Diameter = 2 × Radius
If you know the circumference, you can also calculate the diameter by dividing the circumference by π (pi):
Diameter = Circumference ÷ π
Using these methods helps you easily determine the diameter based on what measurements you have.
How is the circumference of a circle calculated?
The circumference is calculated using the formula 2πr, where “r” is the radius. It represents the distance around the circle.
How to Calculate the Circumference of a Circle?
The circumference of a circle is the total distance around its edge. To find it, multiply the diameter by π (pi), or alternatively, multiply twice the radius by π. The formulas are:
Circumference = π × diameter
Circumference = 2 × π × radius
Using these formulas lets you quickly determine the perimeter of any circle once you know its radius or diameter.
About Circle Calculator
This tool lets you quickly find important measurements related to circles, such as:
- Calculating the area (using A = πr²)
- Finding the circumference (with formulas like C = 2πr or C = πd)
- Determining the diameter (d = 2r)
- Working out the radius (r = d/2)
- Switching easily between these values
You can enter different known values to get the rest:
- Starting from the radius, calculate diameter, area, and circumference
- Starting from the diameter, find radius, area, and circumference
- Given the area, discover the radius, diameter, and circumference
- Given the circumference, find radius, diameter, and area
Here are the main formulas the calculator uses:
Area:
A = πr²
A = (πd²) / 4
Circumference:
C = 2πr
C = πd
Diameter:
d = 2r
d = C / π
Radius:
r = d / 2
r = C / (2π)