Use this geometry calculation when the shape, dimensions, coordinate system, and units match the stated ideal Euclidean model.

Outer radius (m)

Outer radius of the ring.

Inner radius (m)

Inner radius of the hole.

Calculate the area of an annulus from its outer and inner radii as π(R²−r²). The tool evaluates the supplied inputs together and returns the named outputs below; it does not infer omitted operating conditions or change the units shown.^[1]

Area

The resulting area returned as a number.

• The result assumes exact idealized geometry. Measurement uncertainty, rounded inputs, nonplanarity, self-intersection, thickness, curved coordinate systems, and ambiguous dimension definitions are not automatically represented.
• Use finite inputs in the displayed units and preserve more precision than the final presentation requires. Independently verify safety-critical, financial, compliance, or production decisions.

Sketch and label the dimensions, verify unit consistency, and use coordinate or CAD methods for irregular measured shapes.

• Regular Hexagon Area Calculator

  Calculate the area of a regular hexagon from its side length as (3√3/2)·s².

• Kite Area Calculator

  Calculate the area of a kite from the lengths of its two perpendicular diagonals.

• Circle Calculator

  Calculate a circle's radius, diameter, circumference, and area from one known measurement.