A sphere encloses the most volume for a given surface area, which is why bubbles and planets are round.
How to use the Sphere Calculator
- Radius
- Want to work backwards? Type a value into Volume and Radius is calculated for you.
Results update as you type, and every field accepts the units shown in its menu.
How it works
Cube the radius and multiply by 4π/3 for volume; square it and multiply by 4π for surface area.
What each result means
- Volume = 4÷3×pi×[Radius]^3
- Surface area = 4×pi×[Radius]^2
- Great-circle circumference = 2×pi×[Radius]
- Hemisphere volume = 2÷3×pi×[Radius]^3
Example values
How the main result changes when Radius changes and everything else stays at the example values above:
| Radius (m) | Volume (m³) |
|---|---|
| 1.5 | 14.14 |
| 2.25 | 47.71 |
| 3 | 113.1 |
| 3.75 | 220.89 |
| 4.5 | 381.7 |
| 6 | 904.78 |
Formula
V = 4/3 π r³Surface area = 4πr²Worked example
Inputs — Radius: 3 m.
Results — Volume = 113.1 m³; Surface area = 113.1 m²; Great-circle circumference = 18.85 m; Hemisphere volume = 56.55 m³.
Frequently asked questions
How do I measure a ball’s radius?
Measure its circumference with a tape and divide by 2π.
What about a hemisphere?
Half the sphere’s volume, also shown.
What formula does the Sphere Calculator use?
V = 4/3 π r³.
Can I work backwards from the result?
Yes. Type the result you want into Volume and the calculator finds the matching radius.