Circle Calculator Enter any one circle measurement — radius, diameter, circumference, or area — and calculate all others, plus arc length, chord, sector area, and segment area.
Input Given value Radius (r) Diameter (d) Circumference (C) Area (A)
Arc / Sector / Chord Arc Length 5.23598776 Chord Length 5 Sector Area 13.08996939 Segment Area 2.26465184
Results Circle with radius = 5
A = 78.53981634
C = 31.41592654
Property Formula Value Radius (r) — 5 Diameter (d) 2r 10 Circumference (C) 2πr 31.41592654 Area (A) πr² 78.53981634
Circle Formulas Property Formula Diameter d = 2r Circumference C = 2πr = πd Area A = πr² Arc length L = rθ (θ in radians) Sector area A = ½r²θ Chord length c = 2r·sin(θ/2) Segment area A = ½r²(θ − sin θ)