Sphere Surface Area Calculator

SA = 4πr². Exactly 4× the area of a great circle of the same radius.

Inputs

Result

Surface area
314.1593
4πr² = 314.1593 = 4× great-circle area.
  • Radius5
  • Diameter10.0000
  • Great-circle area78.539816
  • Surface area314.159265
  • Volume523.598776

Step-by-step

  1. Great circle (cross-section through center) area = πr² = 78.5398.
  2. Surface area = 4 × great circle = 4πr² = 314.1593.

How to use this calculator

  • Enter radius.
  • Read SA + great-circle area + volume.

About this calculator

Sphere surface area = 4πr², exactly four times the area of a great circle (a cross-section through the center). Archimedes proved this around 250 BCE — and was so proud he had it engraved on his tomb. Earth's surface ≈ 4π × (6371 km)² ≈ 5.1 × 10⁸ km². The sphere has the smallest surface area of any closed surface enclosing a given volume — why bubbles are spherical.

Frequently asked

A famous Archimedean result. The lateral surface of the cylinder circumscribing a sphere equals the sphere's surface area, both = 4πr².

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