Sphere Calculator
Find the volume, surface area, diameter, and great-circle circumference of a sphere from its radius.
Inputs explained
- Radius — Distance from the center of the sphere to its surface.
How to use it
- Fill in the fields above — each input has a hint describing exactly what to enter
- Press Calculate to get your result instantly, right on this page
- Copy the result, save the tool to favorites, or share and embed it anywhere
Understanding the result
Example: A sphere with radius 3 has volume ≈ 113.10 and surface area ≈ 113.10.
Frequently asked questions
Why are the volume and surface area the same number for a radius-3 sphere? That's a coincidence at radius 3, since volume is (4/3)πr³ and surface area is 4πr², and these two formulas happen to produce equal values when r = 3. At any other radius the two results differ.
How is the circumference calculated for a sphere, since it isn't flat? The calculator reports the great-circle circumference, which is the circumference of the largest possible circle that can be drawn around the sphere (2πr) — the same as the distance around its equator.
Is the Sphere Calculator free to use? Yes — it is completely free, with no sign-up, no download and no usage limits. You can use it as often as you need.
Is my data private? Yes. The calculation runs entirely in your browser — the values you enter are never sent to our servers, stored or shared with anyone.
What information do I need? Just the following: Radius. Each field includes a hint explaining exactly what to enter.
Can I use it on my phone? Yes — the tool is fully responsive and works on any device, and the same calculator is available in the EasyWorkCalcs mobile app.
Privacy
Everything you enter into the Sphere Calculator is processed entirely in your browser. Nothing is uploaded, stored or shared — your data stays on your device.