# Calculate the area of a circle

Use this calculation to calculate the area of a circle. You can use numerous different inputs and choose to submit the radius, the diameter or the circumference of the circle. In the result you will get all unknown variables presented.

## Related calculations

#### Calculate the volume of a cylinder

Calculate the volume of a cylinder (such as a beer can or a hose) using many different dimensions for both input and output.#### Calculate area

Calculate the area of all common geometrical shapes, such as circles, triangles etc.#### Calculate the surface area of different geometrical shapes

The surface area is the surface part of a three-dimensional object. You can use these calculations to determine that here.#### Calculate the area of a circle

This calculation will calculate the area of a circle using either the diameter, the radius or the circumference as input.#### Calculate the area of a triangle

Calculate the area of a (right-angled) triangle with this calculation.#### Calculate the surface area of a cube or a brick

Use this calculation to calculate the surface area of cubes and bricks.#### Calculate the surface area of a sphere

How much space do we have to live on, on planet Earth? Calculate this and many other things in this calculation for surface area for spheres.#### Calculate the volume of a pyramid

Calculate the volume of a pyramid with a four-sided bases (such as, well, the pyramids!) using several different dimensions for both input and output.#### Calculate the volume of a cone

Calculate the volume of a cone (such as an ice cream cone), it allows multiple different types of inputs and outputs - depending on your need.#### Calculate volume

Calculate the volume of all common geometrical shapes, such as cubes, spheres, pyramids, cones etc.#### Calculate the surface area of a cone

With this calculation you can calculate the surface area of a cone.#### Calculate the surface area of a pyramid

Ever wondered how much you would have to paint if you were to repaint the pyramids? No? Well, you can calculate surface areas of pyramids (with four-sided bases) here if you ever find the need.#### Calcualate the area of a square or rectangle

Use this calculation to calculate the area of a square or a rectangle.#### Calculate the surface area of a cylinder

If you would unfold a cylinder it would become a rectangle. Calculate the surface area of a cylinder (i.e. that rectangle) here.#### Calculate the volume of a sphere

Calculate the volume of a sphere (such as the earth, a marble) using many different dimensions for both input and output.#### Calculate the volume of a cube or brick

Calculate the volume of a cube or brick (such as a dice or an iPhone) using plenty of different input measurements and get the volume in any dimension you want.

## Some random calculations

#### Calculate the surface area of a cylinder

If you would unfold a cylinder it would become a rectangle. Calculate the surface area of a cylinder (i.e. that rectangle) here.#### Calculate compound interest

Compound interest is interest upon interest that will build up to create great wealth (or debt!) over time. This calculation will help you calculate how much you will gain through compound interest.#### Calculate the area of a triangle

Calculate the area of a (right-angled) triangle with this calculation.#### How long will your hair become if you save it?

Calculate how much longer your hair will be at a certain date.#### Convert km/h, meters per second and miles per hour

Even though these conversions are covered in the Converter on this website, they are so common that they have their own converter. You can convert between miles per hour, meters per second and kilomoters per hour.