Calculate the circumference of circles using radius or diameter. Perfect for geometric calculations, engineering projects, and educational purposes.
Calculate the circumference of a circle using either radius or diameter
Circumference is the distance around the edge of a circle - essentially the perimeter of a circle. It represents the linear measurement of the circular boundary and is fundamental in geometry and many practical applications.
Circumference Formulas:
C = 2πr (using radius)
C = πd (using diameter)
Where π (pi) ≈ 3.14159 is the mathematical constant representing the ratio of a circle's circumference to its diameter. Since diameter = 2 × radius, both formulas are equivalent ways to calculate the same value.
Understanding the difference between circumference and area is crucial for circle calculations:
Linear measurement - the distance around the circle's edge.
Formula: C = 2πr
Used for: perimeter calculations, material length, distance measurements
Surface measurement - the space inside the circle.
Formula: A = πr²
Used for: surface coverage, material area, space calculations
Pi (π) is one of the most important mathematical constants, representing the relationship between a circle's circumference and diameter.
π = circumference ÷ diameter for any circle
π ≈ 3.14159265359... (infinite non-repeating decimal)
Irrational number, same for all circles regardless of size