Sphere Calculator: Volume, Surface Area and Hemisphere
Choose which value you know and enter it. The calculator finds the radius and then the volume, surface area and hemisphere values.
- Nothing you type is stored
- Free
- No signup
Volume
1,436.755cm³
- Radius (r)
- 7 cm
- Surface area
- 615.7522 cm²
- Hemisphere volume
- 718.3775 cm³
- Hemisphere TSA
- 461.8141 cm²
Show working
- V = ⁴⁄₃πr³ = ⁴⁄₃ × π × 7³ = 1,436.755 cm³
- S = 4πr² = 4 × π × 7² = 615.7522 cm²
How to use
- Choose what you know: radius, diameter, volume or surface area.
- Enter it and pick a unit (and π if needed).
- Read the results and the steps.
Good to know
Volume = ⁴⁄₃πr³ and surface area = 4πr² (NCERT Class 9 and 10). A hemisphere has half the volume, ⅔πr³, and a total surface area of 3πr² because its flat face adds πr².
Working backwards: r = ∛(3V/4π) from the volume and r = √(S/4π) from the surface area. With π = 22/7, a surface area of 616 cm² gives r = 7 cm.
Doubling the radius makes the surface area 4 times and the volume 8 times larger, a classic exam question. Useful for balls, globes, ball bearings and domes.
Questions
What is the volume of a sphere?
⁴⁄₃πr³. For r = 7 cm and π = 22/7 it is 1,437⅓ cm³.
What is the surface area of a sphere?
4πr², four times the area of its great circle.
How do I find the radius from the volume?
r = ∛(3V ÷ 4π). Choose "volume" and the calculator does it for you.
What happens if the radius doubles?
Surface area becomes 4 times and volume 8 times as large.
Is anything I enter stored?
No. The calculation runs in your browser and nothing is sent to a server.