Enter the radius of a sphere; the tool applies the standard formula V = (4/3)πr³ and reports the volume. Use it to check geometry homework, compare with real-world sizes, and see how small changes in radius sharply change volume (because volume scales with r³).
Non-negative number; use the same length unit you want for volume cubed (e.g. m → m³).
Enter the radius of a sphere; the tool applies the standard formula V = (4/3)πr³ and reports the volume. Use it to check geometry homework, compare with real-world sizes, and see how small changes in radius sharply change volume (because volume scales with r³).
Volume of a sphere (radius r): V = (4/3)πr³ Radius must be non-negative. Units of volume match the cube of your radius units (e.g. cm → cm³, inches → in³).
If r = 3 cm, then V = (4/3)π(3)³ = (4/3)π·27 = 36π ≈ 113.10 cm³. Doubling the radius to 6 cm multiplies the volume by 8 (since 2³ = 8), giving about 904.78 cm³.
Use V = (4/3)πr³ where r is the radius. If you only know the diameter d, first set r = d/2, then substitute into the formula.
The volume is expressed in cubic units matching your radius. For example, radius in centimetres gives cubic centimetres; radius in inches gives cubic inches.
The formula assumes a perfect sphere. Real objects are approximations; the result is an ideal mathematical model for study and estimation.
Volume depends on r³, so increasing r increases V much faster than the radius itself. That is why a slightly larger sphere holds disproportionately more space inside.
The volume of a sphere is one of the most asked geometry results in school maths on both sides of the Atlantic. Whether you are working in centimetres and metres or thinking about inches and feet, the same formula applies once your radius is in a single length unit.
A sphere is the set of all points a fixed distance r from a centre. Its interior space is measured by V = (4/3)πr³. The cube on r appears because volume is three-dimensional: scaling length by k scales volume by k³. That is why inflating a balloon a little adds a lot of internal space.
Let r be the radius. Then the volume is V = (4/3)πr³. If the diameter d is known, substitute r = d/2.
Take r = 3 cm. Then r³ = 27, so V = (4/3)π × 27 = 36π cm³ ≈ 113.10 cm³. If the radius were 3 inches instead, the numeric value would be the same but the unit would be cubic inches—about 113.10 in³.
Open the Sphere Volume Calculator, type a non-negative radius in the radius field, and read the result lines. They restate the formula, show your r, expand r³, and give V to high precision in cubic units. Change r to see how sharply volume responds when radius grows or shrinks.
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