A sphere's surface area is 4 pi r squared and its volume is four-thirds pi r cubed, both depending only on the radius. Unlike a cone or cylinder, a sphere has no flat net since its curved surface cannot unroll flat. Learn both formulas with a worked example.
What a sphere is
A sphere is a perfectly round 3-D shape — every point on its surface is the same distance (the radius, r) from its center, like a ball. Unlike a cone or a cylinder, a sphere has no flat faces or edges, and its curved surface cannot be unrolled into a flat net.
A sphere with radius r; its surface area and volume both depend only on r.
The surface area formula
A sphere's surface area is SA = 4πr² — exactly four times the area of a great circle (a flat circle cut through the sphere's center), which connects back to circumference of a circle.
The volume formula
A sphere's volume is V = (4/3)πr³. Both formulas use only the radius — there is no height or slant height to measure, since every direction from the center reaches the surface at the same distance.