Enter either radius or volume using consistent units, then click calculate to get the other quantity.
In geometry, a sphere is the set of all points in space at a fixed distance from a center point; that distance is the radius.
If r is the radius of a sphere, the volume formula is V = 4/3 · π · r³. This calculator uses that standard formula to convert between radius and volume.
Given radius, you can compute volume from V = 4/3 · π · r³. Given volume, you can invert the formula and solve for r = ³√(3V / 4π). As long as you keep a consistent unit (cm, m, etc.), the result has clear physical meaning.
All inputs must be greater than 0. If the volume is far too large or too small compared with the cube of the radius, it may indicate unit or input errors.
V = 4/3 · π · r³, where r is the radius.
Volume is proportional to the cube of radius, so doubling r makes the volume 8 times larger.
V = 4/3 · π · 3³ = 36π, approximately 113.1 when π ≈ 3.1416.
Using r = ³√(3V / 4π) with V = 36π gives r = 3.
Because volume is measured in cubic units (cm³, m³, etc.), inconsistent units lead to meaningless results.
For spherical tanks, balloons, containers, astronomy (planet volumes) and some engineering tasks.
That is not physically valid for a real sphere, and this tool will report that the value must be greater than zero.
A cylinder has volume V = πr²h, which depends on height h, while a sphere has V = 4/3 · π · r³ and depends only on radius.
Compute the volume with this tool, then convert it to liters or cubic meters to estimate capacity.
It lets you quickly try many radius or volume values, reduces arithmetic errors and speeds up learning and design.
This tool supports both “given radius find volume” and “given volume solve for radius”, useful for geometry problems, spherical containers and more.
Scan the QR code to use this tool on mobile.