# Sphere Calculator

URL: https://speedycalculator.com/calculators/math/sphere/
Last updated: 2026-10-25

> The sphere calculator finds the volume, surface area and circumference of a sphere from its radius. Type a volume to solve for the radius.

## Inputs

- Radius (m, cm, mm, km, in, ft, yd, mi)

## Results

- Volume
- Surface area
- Great-circle circumference
- Hemisphere volume

## Formula

```
V = 4/3 π r³
Surface area = 4πr²
```

## Explanation

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)1.514.142.2547.713113.13.75220.894.5381.76904.78

## Worked 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.

## FAQ

**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.