Arc Length Calculator

Your details

Choose which quantity to calculate. Enter the other two values below.
Choose whether you enter the central angle in degrees or radians.
Attach a real unit to all length outputs. The math is the same regardless.
The distance from the centre of the circle to the arc.
units
Enter the diameter if you know it instead of the radius. Diameter = 2 × radius.
units
The angle at the centre subtended by the arc.
°
Arc lengthMinor arc
5.236units
Chord length5units
Sector area13.09units²
Sagitta (arc height)0.6699units
Sector perimeter15.236units
Angle in radians1.0472
Angle in degrees60
Radius5units
Fraction of full circle0.17%
Arc length5.236
Chord length5
Sagitta0.6699

A 60° arc on a radius-5 circle is 5.236 units long.

  • The arc covers 16.67% of the full circumference (31.4159 units).
  • The chord shortcutting across the arc is 5 units, always less than the arc itself.
  • The sagitta (the bulge height from chord to arc midpoint) is 0.6699 units.
  • Arc length scales proportionally with both radius and central angle: doubling either one doubles the arc.

Next stepUse "Solve for: Radius" or "Solve for: Central angle" to reverse the calculation when you know the arc length.

 = Powered by OnlyCalculators