MihsabaHow to use
One measurement such as radius or diameter determines all core properties of a sphere. The calculator first normalizes the input to radius, then derives volume, surface area, great-circle circumference and great-circle area using full floating-point π.
- Choose whether the known value is radius or diameter.
- Enter a positive value and choose a length unit.
- Calculate; the input is normalized to radius.
- Read volume, surface area and great-circle measurements with the correct units.
How it is calculated
Example
For radius 3 cm, diameter is 6 cm, surface area is 36π ≈ 113.097 cm², volume is also 36π ≈ 113.097 cm³, and great-circle circumference is 6π ≈ 18.850 cm.
Important notes
Volume uses the cubic length unit and surface area the squared unit. This models an ideal geometric sphere; a real object that is not perfectly spherical, or a tank with wall thickness, needs additional modeling.
Frequently asked questions
What is the difference between a circle and a sphere?
A circle is 2D; a sphere is a 3D solid with volume and surface area.
Why does volume grow so quickly with radius?
Because volume scales with r³, while surface area scales with r².
Can I enter diameter directly?
Yes. Choose diameter and the calculator divides it by two to get radius.
Is this calculator free?
Yes. It is free to use and requires no account.