Sphere Calculator
Calculate volume, surface area, and diameter of a sphere from its radius.
This tool is for informational and educational purposes only. It is not a substitute for professional financial, medical, legal, or engineering advice. See Terms of Service.
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This calculator finds the volume, surface area, and diameter of a sphere from just the radius.
- Enter the radius. Type the radius of the sphere into the input field.
- Read the results. The volume is the primary result, shown prominently. Below it, you will find the surface area and diameter.
- Copy or share. Use the action buttons to copy the volume or generate a shareable link with your radius pre-filled.
The volume formula is V = 4/3 * pi * r^3. The surface area formula is SA = 4 * pi * r^2. The diameter is simply 2 * r. Results update instantly as you type.
About Sphere Properties
A sphere is a perfectly round 3D shape where every point on the surface is equidistant from the center. It has the special property of enclosing the maximum volume for a given surface area, which explains why soap bubbles, planets, and water droplets tend toward spherical shapes. The volume grows cubically with the radius (doubling the radius increases volume by 8 times), while the surface area grows quadratically (doubling the radius increases surface area by 4 times). Spheres are fundamental in physics, astronomy, chemistry (atomic models), sports equipment design, and architecture (domes).
Frequently Asked Questions
What is the volume of a sphere?
The volume of a sphere is V = 4/3 * pi * r^3, where r is the radius. For a sphere with radius 5, the volume is 4/3 * pi * 125 = approximately 523.5988 cubic units.
What is the surface area of a sphere?
The surface area of a sphere is SA = 4 * pi * r^2. This equals exactly 4 times the area of the sphere's great circle. For radius 5, the surface area is 4 * pi * 25 = approximately 314.1593 square units.
How does doubling the radius affect volume?
Doubling the radius increases the volume by a factor of 8 (2^3 = 8), because volume depends on the cube of the radius. A sphere with radius 10 has 8 times the volume of a sphere with radius 5.