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Annulus Area Calculator Reference Values

Calculate annulus area from outer and inner radius using A = π(R² - r²).

Author

Prof. Chen Wei

Math editorial contributor

Chinese AI ethics researcher at Tsinghua University, publishing extensively on algorithmic bias in hiring systems

Reviewed for accuracy by

Dr. Emeka Nwosu

Math content reviewer

Nigerian legal scholar with an SJD from Yale, focused on international trade law and African continental free trade agreements

Last updatedFebruary 22, 2026

PublishedFebruary 22, 2026

Table of Contents

  1. All value pages
  2. Reference table
  3. FAQs
  4. Methodology and review
  5. Related conversions

Reference Value Index

This page lists 22 reference values for quick browsing and lookup.

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All Reference Values

Reference Table

Annulus Area Calculator reference values
ScenarioAnnulus Area
2 units Outer Radius (R); 0.5 units Inner Radius (r)11.781 sq units
2 units Outer Radius (R); 1 units Inner Radius (r)9.4248 sq units
2 units Outer Radius (R); 1.5 units Inner Radius (r)5.4978 sq units
3 units Outer Radius (R); 0.5 units Inner Radius (r)27.4889 sq units
3 units Outer Radius (R); 1 units Inner Radius (r)25.1327 sq units
3 units Outer Radius (R); 1.5 units Inner Radius (r)21.2058 sq units
3 units Outer Radius (R); 2 units Inner Radius (r)15.708 sq units
4 units Outer Radius (R); 0.5 units Inner Radius (r)49.4801 sq units
4 units Outer Radius (R); 1 units Inner Radius (r)47.1239 sq units
4 units Outer Radius (R); 1.5 units Inner Radius (r)43.1969 sq units
4 units Outer Radius (R); 2 units Inner Radius (r)37.6991 sq units
4 units Outer Radius (R); 3 units Inner Radius (r)21.9911 sq units
5 units Outer Radius (R); 0.5 units Inner Radius (r)77.7544 sq units
5 units Outer Radius (R); 1 units Inner Radius (r)75.3982 sq units
5 units Outer Radius (R); 1.5 units Inner Radius (r)71.4712 sq units
5 units Outer Radius (R); 2 units Inner Radius (r)65.9734 sq units
5 units Outer Radius (R); 3 units Inner Radius (r)50.2655 sq units
8 units Outer Radius (R); 0.5 units Inner Radius (r)200.2765 sq units
8 units Outer Radius (R); 1 units Inner Radius (r)197.9203 sq units
8 units Outer Radius (R); 1.5 units Inner Radius (r)193.9933 sq units
8 units Outer Radius (R); 2 units Inner Radius (r)188.4956 sq units
8 units Outer Radius (R); 3 units Inner Radius (r)172.7876 sq units

Frequently Asked Questions

Frequently asked questions for Annulus Area Calculator and its reference values.

What does the Annulus Area Calculator calculator do?

It helps with finding ring-shaped area for washers, gaskets, and circular cutouts.

What formula does the Annulus Area Calculator calculator use?

Annulus area = π × (outer radius² - inner radius²).

What inputs are valid?

Outer radius must be greater than inner radius, and inner radius cannot be negative.

When would I use this?

finding ring-shaped area for washers, gaskets, and circular cutouts

Methodology and Review

Each row on this page links to a value detail page derived from the same conversion data file as the main calculator and reference table. This reduces inconsistencies across page variants.

Editorial metadata and structured data are rendered across the converter page and linked value pages. Review policies are documented in our review process and editorial policy.