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Dieser Rechner wird derzeit auf Englisch angezeigt, während die Übersetzung vorbereitet wird.

Mathematik

Verifizierter Rechner mit transparenter Formel

Mathematik

Circle Circumference Calculator.

Calculates the circumference of a circle from its radius or diameter, with optional precision for the value of pi.

Ergebnisse werden während der Eingabe live aktualisiert.
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Ihre Eingaben

So funktioniert es

  1. 1

    Enter the radius or diameter of the circle.

  2. 2

    Choose the precision for pi (3.14, 3.1416, or 3.14159).

  3. 3

    The calculator uses the larger of radius or diameter/2 to compute the circumference.

  4. 4

    The result is displayed with two decimal places.

max(radius, diameter/2) * 2 * pi_precision

Häufig gestellte Fragen

What is the formula for circumference?

Circumference = 2 × π × radius, or π × diameter.

Why do you use the larger of radius and diameter/2?

To avoid confusion if both are entered inconsistently; the calculator uses the value that gives the correct circumference.

Can I use any unit?

Yes, the unit is generic. Just be consistent with your input.

Diese Rechner-Kategorie erkunden

Ergebnisse

Formel geprüft

Circumference

31,416units

Using radius31,42units
Using diameter31,42units
Fragen Sie alles

Schätzung nur zur allgemeinen Orientierung – wichtige Entscheidungen mit einem geeigneten Fachmann verifizieren.

So funktioniert es

Calculates the circumference of a circle from its radius or diameter, with optional precision for the value of pi.

  1. Enter the radius or diameter of the circle.
  2. Choose the precision for pi (3.14, 3.1416, or 3.14159).
  3. The calculator uses the larger of radius or diameter/2 to compute the circumference.
  4. The result is displayed with two decimal places.

Formeln

Die Mathematik hinter diesem Rechner, aufgeschrieben, damit Sie das Ergebnis überprüfen können.

Circumference from radius

C = 2πr

Multiply the radius by 2 and by pi.

Example:

Input: r = 5, π = 3.14159

Calculation: 2 × 5 × 3.14159

Result: ≈ 31.4159

Circumference from diameter

C = πd

Multiply the diameter by pi.

Example:

Input: d = 10, π = 3.14159

Calculation: 10 × 3.14159

Result: ≈ 31.4159

Anwendungsfälle im Alltag

Wo diese Berechnung im täglichen Leben vorkommt.

Wheel size

Find the distance a wheel covers in one revolution.

Example: A wheel with diameter 0.7 m has circumference ≈ 2.2 m.

Fencing a circular garden

Determine the length of fencing needed around a circular area.

Example: A garden with radius 3 m needs ≈ 18.85 m of fencing.

Pipe or cable length

Calculate the length of material needed to wrap around a circular object.

Example: A pipe with radius 0.05 m has circumference ≈ 0.314 m.

Tipps und häufige Fehler

Tips

  • Use a more precise pi for larger circles to reduce rounding error.
  • If you only have the diameter, you can still use the radius field by dividing by 2.
  • Remember that circumference is a linear measurement, so units stay the same.

Common Mistakes to Avoid

  • Confusing radius and diameter: radius is half the diameter.
  • Using the diameter in the radius formula without dividing by 2.
  • Forgetting to multiply by 2 when using the radius.

Annahmen und Einschränkungen

  • Use the stated inputs and units.
  • Results are estimates for planning and education.
  • Check measurements and source data before making an important decision.