Kreisflächen-Rechner

Überblick

The area of a circle measures the space inside it, and the circumference measures the distance around it — both derived from the radius. This calculator finds them instantly from the radius, diameter, or circumference in your browser.

So gehts (Schritt für Schritt)

1. 1

   Enter a known measurement

   Provide the radius, diameter, or circumference.

2. 2

   Calculate

   The tool derives the radius and computes area and circumference.

3. 3

   Read the results

   Both area and circumference are shown together.

Funktionsweise

Area = π × r², and circumference = 2 × π × r, where r is the radius and π is about 3.14159. If you know the diameter instead, the radius is half of it; if you know the circumference, the radius is circumference ÷ (2π). The tool accepts whichever measurement you have and computes the rest.

Wann verwenden

Working out material needed for a circular area like a garden bed or table. Solving a geometry problem. Finding the circumference for fencing or trim around a round object.

Häufig Gestellte Fragen