From radius
Radius r
V = 4πr³/3; S = 4πr²
Open calculator ↗GEOMETRY, ONE FIGURE AT A TIMESphere.
Sphere.
Understand every measure.
Every surface point, one distance from the centre. Four free tools, clear formulas and a little discovery along the way.
Find your calculator ↗FIGURE 183D / REFERENCE DRAWING
SPHERENOT TO SCALE
THE CALCULATOR DESK
Start with what you know.
4 calculators available
From diameter
Diameter d
r = d/2
Open calculator ↗From volume
Volume V
r = ∛(3V/4π)
Open calculator ↗From surface area
Surface area S
r = √(S/4π)
Open calculator ↗MEET THE FIGURE
A sphere, explained.
A sphere is the surface of points in three-dimensional Euclidean space at a fixed radius from a centre. Its enclosed solid is a ball. Here “sphere volume” means the volume of that ball, a common calculator convention.
Understand the properties ↗LOOK A LITTLE CLOSER
More than a formula.
Every great circle has the same radius as the sphere.
A hollow shell’s material volume requires an inner radius as well as an outer radius; this tool models a solid ball.
Explore three geometry facts ↗These tools use ideal Euclidean geometry. Every input must use the same unit. Numerical results are rounded and do not replace measurement, specialist design or safety checks. See worked examples.