Circle Calculators

Arc Length Calculator Our arc length calculator can calculate the length of an arc of a circle and the area of a sector. Area of a Circle Calculator The area of a circle calculator will compute the surface of a circle using a radius or a diameter. Circle Calculator This circle calculator finds c (circumference), d (diameter), a (area), and r (radius) of a circle. Circle Theorems Calculator With our circle theorems calculator, you can understand all of the different circle theorems! Circumference Calculator Use this free circumference calculator to find the area, circumference and diameter of a circle. Circumference-to-Radius Calculator Convert from circumference to radius and vice versa with this circumference-to-radius calculator. It can also show the diameter and area when needed. Coin Rotation Paradox How many times will a coin rotate around another coin n a single revolution? The answer is not as easy as it may look! Equation of a Circle Calculator Equation of a circle calculator finds a circle's radius and center coordinates on a Cartesian plane. Sector Area Calculator Sector area calculator can find the sector area of a circle in the blink of an eye. Semicircle Area Calculator This semicircle area calculator determines the area of a half circle, as well as the circumference of a semicircle. Square in a Circle Calculator Use our square in a circle calculator to seamlessly determine fitting dimensions for squares in circles and circles in squares. String Girdling Earth Calculator The string girdling Earth calculator can help you determine the extra string length needed to achieve a desired gap or the resulting gap achieved by splicing a given string length. Tangent of a Circle Calculator Use this tangent of a circle calculator to determine the length of tangent from a point on a circle.