Circle Calculator
Calculate circle properties: radius, diameter, circumference, area, arc length, sector area, and chord length. Free online circle calculator.
Circle Formulas
Diameter: d = 2r
Circumference: C = 2πr = πd
Area: A = πr²
Arc Length: L = (θ/360°) × 2πr
Sector Area: A = (θ/360°) × πr²
Chord Length: c = 2r × sin(θ/2)
Value of π
π ≈ 3.14159265358979323846...
π ≈ 22/7 (approximation)
π ≈ 355/113 (better approximation)
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