Sphere Volume Calculator

How it works

A sphere is fully described by one number — its radius — and from it follow both results here: volume V = 4/3·π·r³ and surface area S = 4·π·r². For a radius of 10 cm, the volume is about 4,189 cm³ and the surface about 1,257 cm². Notice the powers: volume grows with the cube of the radius, surface only with the square. Double the radius and the surface quadruples while the volume multiplies by eight. This cube-square law is why large animals lose heat more slowly and why doubling a balloon's width takes far more than double the air. If you know the diameter instead, divide by 2 to get the radius; from a circumference, divide by 2π. The sphere is also nature's most efficient shape — it encloses the most volume for the least surface, which is why bubbles and droplets are round.