Mathematics · Geometry

Torus Volume and Surface Area Calculator

Calculate the volume and surface area of a circular torus.

Runs locally
Your numbers

Inputs and results stay in this browser. Change one value at a time to explore the relationship.

Live constructionTorus
TorusA ring torus with major radius 5 and minor radius 2.R = 5r = 2

Change an input to reshape this diagram.

Your inputCalculatedPassed forward in chains
Volume394.784176
Surface area394.784176
Outer radius7
Inner radius3

Calculation steps

  1. Volume=2π²×5×2²=394.78417604357435.
  2. Area=4π²×5×2=394.78417604357435.

Understand Torus geometry

One idea, three depths

Choose how deeply to explain Torus geometry

Torus geometry: Calculate the volume and surface area of a circular torus.

Age 5Explain it to a 5-year-oldStart with a picture

Imagine using Torus geometry to answer this question: calculate the volume and surface area of a circular torus? Enter Major radius R and Minor radius r; the calculator shows Volume. For example: R=5 and r=2 gives volume 40π² and area 40π². The answer tells you Volume.

Age 15Explain it to a 15-year-oldConnect it to the formula

Pappus's centroid theorem sweeps a circular cross-section around the major axis. The rule is V=2π²Rr²; A=4π²Rr. Its input values are Major radius R, Minor radius r, and the main result is Volume. For example: R=5 and r=2 gives volume 40π² and area 40π².

CollegeExplain it at college levelState the model precisely

This calculator evaluates the stated torus geometry relation over the valid real-number domain stated below. The implemented relation is V=2π²Rr²; A=4π²Rr, evaluated from Major radius R, Minor radius r to produce Volume. Pappus's centroid theorem sweeps a circular cross-section around the major axis. The major radius runs from the torus center to the tube center, not to its outer edge.

Inputs and valid domain

  • Major radius R must be a finite real number, at least 0.
  • Minor radius r must be a finite real number, at least 0.

Important boundary: The major radius runs from the torus center to the tube center, not to its outer edge.

The formula

V=2π²Rr²; A=4π²Rr

How the calculator works through it

It substitutes Major radius R, Minor radius r into the formula and exposes every numerical step above. The main output is Volume, accompanied by Surface area, Outer radius, Inner radius.

Read the result correctly

The Volume is the direct answer to “calculate the volume and surface area of a circular torus.” Read it with the units shown beside the inputs; a sign, angle, percentage or rate changes what the number means.

A worked check

R=5 and r=2 gives volume 40π² and area 40π².

Where this model stops being reliable

The major radius runs from the torus center to the tube center, not to its outer edge.

Learn it by changing one value

Begin with the worked example, then change one value while keeping the others fixed. Compare the new result and calculation steps to identify which part of the formula changed.

Dictionary terms behind this calculator

Before studying the codeWhat you should know firstUse the calculator immediately, or check the foundations before reading the implementation.

These foundations help you understand why Torus geometry works. They never block the calculator, and “optional” means useful context rather than a hidden requirement.

Hard requirements

  • Reading formulas and substituting values

    Torus geometry uses V=2π²Rr²; A=4π²Rr. You need to recognise what each side represents before substituting the stated inputs or rearranging the relationship.

    Review this foundation about 4 min

Strong support

Optional enrichment

  • Angles and geometric relationships

    Angle language provides useful geometric context for extending Torus geometry to related shapes and constructions.

    Review this foundation about 4 min
Learn the missing foundationsI already know these — show the code

Mathematics → algorithm → program

Implement this calculation in code

These are direct reference implementations of the calculator's principal relationship and first output. They run locally and include a small known-answer check where the language supports it.

Algorithm

  1. Read Major radius R, Minor radius r.
  2. Evaluate the principal relationship: V=2π²Rr²; A=4π²Rr.
  3. Return Volume and check the domain conditions described above.
Python
            from math import *

def torus_geometry(a, b) -> float:
    return (2.0 * ((pi * pi) * (a * (b * b))))

assert abs(torus_geometry(5, 2) - 394.78417604357435) < 1e-6 * max(1.0, abs(394.78417604357435))
          
Current calculator valuesUpdates when you change an input above.
              
            
C
            #include <assert.h>
#include <math.h>

double torus_geometry(double a, double b) {
    return (2.0 * ((3.141592653589793 * 3.141592653589793) * (a * (b * b))));
}

int main(void) {
    const double expected = 394.78417604357435;
    const double actual = torus_geometry(5, 2);
    assert(fabs(actual - expected) < 1e-6 * fmax(1.0, fabs(expected)));
}
          
Current calculator valuesUpdates when you change an input above.
              
            
C++
            #include <cassert>
#include <cmath>
#include <numbers>

double torus_geometry(double a, double b) {
    return (2.0 * ((std::numbers::pi * std::numbers::pi) * (a * (b * b))));
}

int main() {
    constexpr double expected = 394.78417604357435;
    const double actual = torus_geometry(5, 2);
    assert(std::fabs(actual - expected) < 1e-6 * std::fmax(1.0, std::fabs(expected)));
}
          
Current calculator valuesUpdates when you change an input above.
              
            
Linux x86-64 assembly

x86-64 NASM · System V ABI · Linux · SSE2 with libm where required

            ; double torus_geometry(double a, double b)
; Linux x86-64 NASM · System V ABI · first eight doubles in xmm0–xmm7
global torus_geometry
section .text

torus_geometry:
    push rbp
    mov rbp, rsp
    sub rsp, 80
    movsd [rbp-8], xmm0
    movsd [rbp-16], xmm1
    mov rax, 0x4000000000000000
    movq xmm0, rax
    movsd [rbp-32], xmm0
    mov rax, 0x400921fb54442d18
    movq xmm0, rax
    movsd [rbp-56], xmm0
    mov rax, 0x400921fb54442d18
    movq xmm0, rax
    movsd [rbp-64], xmm0
    movsd xmm0, [rbp-56]
    mulsd xmm0, [rbp-64]
    movsd [rbp-48], xmm0
    movsd xmm0, [rbp-16]
    mulsd xmm0, [rbp-16]
    movsd [rbp-80], xmm0
    movsd xmm0, [rbp-8]
    mulsd xmm0, [rbp-80]
    movsd [rbp-72], xmm0
    movsd xmm0, [rbp-48]
    mulsd xmm0, [rbp-72]
    movsd [rbp-40], xmm0
    movsd xmm0, [rbp-32]
    mulsd xmm0, [rbp-40]
    movsd [rbp-24], xmm0
    movsd xmm0, [rbp-24]
    leave
    ret
          
Current calculator valuesUpdates when you change an input above.
              
            
MATLAB
            function result = torus_geometry(a, b)
    result = (2.0 * ((pi * pi) * (a * (b * b))));
end
          
Current calculator valuesUpdates when you change an input above.
              
            
Wolfram Language
            ClearAll[mwCalculate];
mwCalculate[a_, b_] := (2.0 * ((Pi * Pi) * (a * (b * b))));
          
Current calculator valuesUpdates when you change an input above.
              
            

Continue in mathematical software

The downloaded file includes your current inputs and first calculated result. It is created locally.

Floating-point answers can differ slightly by language, compiler and processor. Compare within a suitable tolerance rather than assuming every decimal representation will be identical.

Supporting sourcesAcademic referencesPrimary standards, textbooks and complete citations

Standards, reading and academic references

Use the calculator as the worked interaction, then consult the primary standards and academic textbooks listed below. MW SysArc links to the original sources; the explanation on this page is original and does not reproduce them.

Algebra and Trigonometry 2e

Read the related free OpenStax mathematics chapters
Cite this book
APA 7
Abramson, J. (2021). Algebra and trigonometry 2e. OpenStax. https://openstax.org/books/algebra-and-trigonometry-2e/pages/1-introduction-to-prerequisites
MLA 9
Abramson, Jay. Algebra and Trigonometry 2e. OpenStax, 2021, https://openstax.org/books/algebra-and-trigonometry-2e/pages/1-introduction-to-prerequisites.
Chicago author-date
Abramson, Jay. 2021. Algebra and Trigonometry 2e. Houston, TX: OpenStax. https://openstax.org/books/algebra-and-trigonometry-2e/pages/1-introduction-to-prerequisites.

OpenStax entries are free to read online. Follow the licence shown on each linked source before redistributing or adapting its content.

Reuse the page responsiblyCite this pageAPA, MLA, Chicago, Harvard, BibTeX and RIS

These formats cite this calculator page itself. They are separate from the academic references above, which support the mathematical method and terminology.

APA 7

MW SysArc. (2026, July 21). Torus Volume and Surface Area Calculator. MW SysArc Tools. https://math.mwsysarc.com/geometry/torus-volume-surface-area

MLA 9

MW SysArc. “Torus Volume and Surface Area Calculator.” MW SysArc Tools, 21 July 2026, https://math.mwsysarc.com/geometry/torus-volume-surface-area. Accessed 31 Aug. 2026.

Chicago 17

MW SysArc. “Torus Volume and Surface Area Calculator.” MW SysArc Tools. Published July 21, 2026. Accessed August 31, 2026. https://math.mwsysarc.com/geometry/torus-volume-surface-area.

Harvard

MW SysArc (2026) ‘Torus Volume and Surface Area Calculator’, MW SysArc Tools. Published 21 July 2026. Available at: https://math.mwsysarc.com/geometry/torus-volume-surface-area (Accessed: 31 August 2026).

BibTeX and RIS records

BibTeX

@misc{mwsysarc_torus_geometry_2026,
  author = {{MW SysArc}},
  title = {Torus Volume and Surface Area Calculator},
  howpublished = {MW SysArc Tools},
  year = {2026},
  url = {https://math.mwsysarc.com/geometry/torus-volume-surface-area},
  note = {Published July 21, 2026; accessed August 31, 2026}
}

RIS

TY  - ELEC
AU  - MW SysArc
TI  - Torus Volume and Surface Area Calculator
T2  - MW SysArc Tools
PY  - 2026
DA  - 2026-07-21
Y2  - 2026-08-31
UR  - https://math.mwsysarc.com/geometry/torus-volume-surface-area
N1  - Published July 21, 2026
ER  -

Clear answers

Frequently asked questions

What does the Torus geometry do?

Calculate the volume and surface area of a circular torus.

How does the Torus geometry work?

The calculator applies V=2π²Rr²; A=4π²Rr. Pappus's centroid theorem sweeps a circular cross-section around the major axis.

What can I learn from the Torus geometry?

It connects the mathematical rule to your chosen numbers and shows each calculation step. Change one input at a time to see how the result responds.

Does MW SysArc receive or store what I enter?

No. The calculation runs locally in your browser. MW SysArc does not receive or store your calculation inputs.

How should I use the result?

Use the steps to understand the method, then verify important school or professional work using the notation and rounding rules required in your setting.

Last reviewed . Calculations tested .

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