3D · curved solid

Sphere

A sphere’s surface consists of points at a fixed distance from its center. Its volume grows with the cube of the radius, while surface area grows with the square.

RectangleChange a dimension to explore
A = w × hDimensions shown in the selected unit

Give your shape a size.

Use the same unit for every dimension. Changing the unit relabels the measurements; it does not convert them.

From dimensions to an answer

Know its properties

Flat facesNone
Edges / verticesNone
Great-circle radiusSame as the sphere radius
Cross-sectionsCircles, or a point at tangency

Useful formulas

Volume: V = 4πr³ / 3

Surface area: S = 4πr²

A little question. A clearer picture.

Sphere: common questions

Wondering about the why? Start here.

How do I calculate a sphere’s volume and surface area?

For radius r, volume is 4πr³/3 and surface area is 4πr². Enter the radius, not the diameter. A sphere with radius 3 has volume 36π cubic units and surface area 36π square units.

Understand volume and surface area
What happens when a sphere’s radius doubles?

Its surface area becomes four times as large because area depends on r². Its volume becomes eight times as large because volume depends on r³. These scale factors apply when every length of a similar solid changes by the same factor.

Learn the scaling rules