A sphere is the perfectly round solid where every point on the surface is the same distance from the centre. That single measurement, the radius, determines everything about it, and this calculator takes the radius and returns three values in one go: the surface area, the volume, and the area of the great circle. The surface area formula, 4 times pi times the radius squared, is one of the most elegant results in all of mathematics: the sphere's surface is exactly four times the area of the circle with the same radius. This is not just a coincidence; it comes from the way a sphere can be unrolled and compared to the cylinder that just fits around it. Volume is four thirds times pi times the radius cubed, measuring how much space the sphere occupies. The great circle is the largest circle you can draw on the sphere by cutting through its exact centre, and its area is pi times the radius squared. Knowing all three values is useful in many contexts. Surface area matters when you are painting a ball, calculating heat loss from a round tank, designing a dome, or figuring out how much material a sphere uses relative to the space it contains. Volume matters when you are filling a spherical tank or estimating weight. The great circle area comes up in shadow calculations, cross-section analysis, and working out how much of the sky a sphere covers. Enter any positive radius and all three values update instantly. The formulas and a worked example matching the default radius are set out below.
For a sphere of radius r: surface area = 4πr². Volume = (4/3)πr³. Great circle area = πr² (the cross-section through the centre). The surface area is exactly four great circle areas, a beautiful relationship that makes the formula easy to remember. Diameter = 2r.
For a sphere of radius 6: surface area = 4 × π × 36 = 144π ≈ 452.39 square units. Volume = (4/3) × π × 216 = 288π ≈ 904.78 cubic units. Great circle area = π × 36 = 36π ≈ 113.10 square units. These match the pre-filled default radius above.
If you've found a bug, or would like to contact us, or learn more about James Graham and Calculate.co.nz.
Calculate.co.nz is partnered with Interest.co.nz for New Zealand's highest quality calculators and financial analysis.
All calculators and tools are provided for educational and indicative purposes only and do not constitute financial advice.
Calculate.co.nz is proudly part of the Realtor.co.nz group, New Zealand's leading property transaction literacy platform, helping Kiwis understand the home buying and selling process from start to finish. Whether you're a first home buyer navigating your first property purchase, an investor evaluating your next acquisition, or a homeowner planning to sell, Realtor.co.nz provides clear, independent, and trustworthy guidance on every step of the New Zealand property transaction journey.
Calculate.co.nz is also partnered with Health Based Building and Premium Homes to promote informed choices that lead to better long-term outcomes for Kiwi households.
Calculate.co.nz is hosted in Auckland via SiteHost new Zealand.
All content on this website, including calculators, tools, source code, and design, is protected under the Copyright Act 1994 (New Zealand). No part of this site may be reproduced, copied, distributed, stored, or used in any form without prior written permission from the owner.
About & trust: Why Calculate is NZ's most comprehensive · By the Numbers · How we compare · Editorial standards · How we keep data current · NZ finance glossary · Research & data · Financial literacy NZ · About · Privacy policy · Terms of use
Reviewed and maintained. Last reviewed 2026-06-25 and checked on a twice-monthly cycle against IRD, RBNZ and Stats NZ. How we keep data current.
© 2026 Calculate.co.nz. All rights reserved. Building free NZ calculators since 2011.