Convertools

Annulus Area from Outer and Inner Diameters

Calculate annulus area from outer and inner diameters.

Author

Dr. Elif Yilmaz

Math editorial contributor

Turkish computational biologist at the Max Planck Institute, mapping gene regulatory networks in rare diseases

Reviewed by

Prof. Hans Muller

Math content reviewer

German renewable energy engineer at TU Munich, pioneering grid-scale hydrogen storage solutions

Last updatedFebruary 22, 2026

PublishedFebruary 22, 2026

Table of Contents

  1. Reference values
  2. Calculator
  3. Reference table
  4. FAQs
  5. Methodology and review
  6. Related conversions

20 units Outer Diameter; 0 units Inner Diameter =

314.159265 sq units

Representative value from the Annulus Area from Outer and Inner Diameters reference table.

Reference Values

Browse 36 reference values with individual detail pages for quick lookup.

Browse all reference values

Annulus Area from Outer and Inner Diameters

Calculate annulus area from outer and inner diameters.

Calculated Result

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Reference Table

Use this complete table for quick lookup and internal linking to specific value pages.

Annulus Area from Outer and Inner Diameters Reference
ScenarioAnnulus Area
2 units Outer Diameter; 0 units Inner Diameter3.141593 sq units
2 units Outer Diameter; 0.5 units Inner Diameter2.945243 sq units
2 units Outer Diameter; 1 units Inner Diameter2.356194 sq units
2 units Outer Diameter; 1.5 units Inner Diameter1.374447 sq units
2 units Outer Diameter; 1.8 units Inner Diameter0.596903 sq units
2 units Outer Diameter; 2 units Inner Diameter0 sq units
4 units Outer Diameter; 0 units Inner Diameter12.566371 sq units
4 units Outer Diameter; 1 units Inner Diameter11.780972 sq units
4 units Outer Diameter; 2 units Inner Diameter9.424778 sq units
4 units Outer Diameter; 3 units Inner Diameter5.497787 sq units
4 units Outer Diameter; 3.6 units Inner Diameter2.38761 sq units
4 units Outer Diameter; 4 units Inner Diameter0 sq units
10 units Outer Diameter; 0 units Inner Diameter78.539816 sq units
10 units Outer Diameter; 2.5 units Inner Diameter73.631078 sq units
10 units Outer Diameter; 5 units Inner Diameter58.904862 sq units
10 units Outer Diameter; 7.5 units Inner Diameter34.36117 sq units
10 units Outer Diameter; 9 units Inner Diameter14.922565 sq units
10 units Outer Diameter; 10 units Inner Diameter0 sq units
20 units Outer Diameter; 0 units Inner Diameter314.159265 sq units
20 units Outer Diameter; 5 units Inner Diameter294.524311 sq units
20 units Outer Diameter; 10 units Inner Diameter235.619449 sq units
20 units Outer Diameter; 15 units Inner Diameter137.444679 sq units
20 units Outer Diameter; 18 units Inner Diameter59.69026 sq units
20 units Outer Diameter; 20 units Inner Diameter0 sq units
40 units Outer Diameter; 0 units Inner Diameter1,256.637061 sq units
40 units Outer Diameter; 10 units Inner Diameter1,178.097245 sq units
40 units Outer Diameter; 20 units Inner Diameter942.477796 sq units
40 units Outer Diameter; 30 units Inner Diameter549.778714 sq units
40 units Outer Diameter; 36 units Inner Diameter238.761042 sq units
40 units Outer Diameter; 40 units Inner Diameter0 sq units
100 units Outer Diameter; 0 units Inner Diameter7,853.981634 sq units
100 units Outer Diameter; 25 units Inner Diameter7,363.107782 sq units
100 units Outer Diameter; 50 units Inner Diameter5,890.486225 sq units
100 units Outer Diameter; 75 units Inner Diameter3,436.116965 sq units
100 units Outer Diameter; 90 units Inner Diameter1,492.25651 sq units
100 units Outer Diameter; 100 units Inner Diameter0 sq units

Frequently Asked Questions

Common questions about Annulus Area from Outer and Inner Diameters, formulas, and typical use cases.

What does the Annulus Area from Outer and Inner Diameters calculator do?

It helps with calculating ring-shaped cross-sectional area from measured diameters.

What formula does the Annulus Area from Outer and Inner Diameters calculator use?

Annulus area = π(Do² - Di²)/4.

What inputs are valid?

Diameters must be non-negative and inner diameter cannot exceed outer diameter.

When would I use this?

calculating ring-shaped cross-sectional area from measured diameters

Methodology and Review

This page combines a live calculator, precomputed reference values, and FAQ content from the same conversion definition to reduce mismatch between calculator output and lookup tables.

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