Sphere Surface Area Calculator
Enter a radius to get the surface area of a sphere (4πr²) — plus the volume — in any unit you choose, and see how the area grows with the square of the radius.
Area and volume at once
Enter the radius and the sphere surface area calculator returns the surface area (4πr²) and the volume (4/3 πr³) together, in your chosen unit.
Pick one unit
The answer follows your input unit: a radius in cm gives area in cm² and volume in cm³. Keep one unit throughout and the results stay consistent.
What is the surface area of a sphere?
The size of its outer skin
The surface area of a sphere is the total size of its curved outer skin — the amount of material you would need to wrap it completely with no overlap. This sphere surface area calculator turns a single measurement, the radius, into that area using the formula 4πr², and it returns the volume alongside it. Because the radius is squared, the area grows steeply: a sphere twice as wide has four times the surface. The number sits behind everyday questions like how much paint covers a ball, how much foil wraps a globe, or how fast a planet radiates heat — and it works in whatever unit you measure the radius in.
Enter a radius in any unit to get the sphere's surface area in that unit squared and the volume in that unit cubed instantly.
The surface area is four times pi times the radius squared, and the volume is four-thirds pi times the radius cubed.
A = 4 × π × r²Suppose a sphere has a radius of 5. Squaring the radius gives 5² = 25, then multiplying by 4π gives 4 × π × 25 = 314.159265 square units. The same radius gives a volume of 4/3 × π × 5³ = 523.598776 cubic units. The radius is squared for the area but cubed for the volume, so as a sphere grows its volume outpaces its surface — the reason large bubbles and droplets behave so differently from tiny ones.
The formula is exact for a perfect sphere, but a couple of practical points are worth keeping in mind.
Perfect spheres and consistent units
This calculator assumes a perfect, solid sphere and uses the radius — half the diameter — not the diameter itself, so halve the diameter before you enter it. Real objects that are slightly squashed (like planets) or hollow shells need their own adjustments. The tool is unit-agnostic: whatever unit you use for the radius, the surface area comes back in that unit squared and the volume in that unit cubed, so keep a single unit throughout.