# Moments of Inertia — Engineering Calculation

> Engineering app for calculating beam section properties and moments of inertia. (iPhone/iPad app by J.R.Hobbs.)

- Source: https://appshunter.io/ios/app/moments-of-inertia/id494181506 (this page in markdown: same URL + `.md`)
- Developer: [J.R.Hobbs](https://appshunter.io/developer/395110523)
- Category: Utilities, Reference
- Price: $5.99
- Rating: 1.00/5 from 1 App Store ratings · 4 written reviews indexed
- Age rating: 4+
- Requires: iOS 12.0 · 9 MB
- Languages: American English
- Released: 2012-01-17
- Data updated: 2026-09-03
- Monetization: paid
- User reviews in markdown: https://appshunter.io/ios/app/moments-of-inertia/id494181506/reviews.md

## What is Moments of Inertia?

If you need a beam's moments of inertia, cross sectional area, centroid, or radius of gyration, you need this app.  This app was created to assist you in these calculations and to ensure that your beam section calculations are fast and accurate.  Simply select from the available geometries, enter in the required dimensions and the answers will be generated complete with the formulae.  You can also easily print or email a PDF of your results along with a schematic of the beam's cross section. 

Moments of Inertia Features:
- Designed for use on all sizes of the iPhone, iPod Touch, and iPad
- Extremely flexible unit system that has the ability to perform unit conversions on the output
- Save multiple cases of each solution for later reference
- Printing Capability
- Ability to email a PDF of the Cross Section Schematic, Inputs, Equations, and Results

The properties calculated include are:
   - Moments of Inertia about the x & y axes
   - Polar Moment of Inertia
   - Radius of Gyration
   - Centroids
   - Area
   - Section Modulus

Moments of Inertia calculates the properties and displays the equations for many sections including:
   • Rectangles
   • Hollow Rectangles
   • Circles
   • Hollow Circles
   • Semicircles
   • Quarter Circles
   • Ellipses
   • Triangles
   • I Beams
   • Tee Sections
   • Channel Sections
   • Unequal-Legged Angle

Check out our other engineering apps by searching the iTunes store for:
   • Pressure Vessel Pro
   • Mohr's Circle
   • Stress Concentrations Pro
   • Stress Intensity Factors Pro
or search J.R.Hobbs to see them all.

## Key features

- Calculate moments of inertia, area, centroid, and radius of gyration
- Supports multiple geometric shapes
- Flexible unit system with conversions
- Save and reference multiple calculation cases
- Print or email PDF reports with schematics and results

## Recent user reviews (4 of 4)

All indexed reviews: https://appshunter.io/ios/app/moments-of-inertia/id494181506/reviews.md

### 1/5 — Moment of inertia

*2015-06-28*

Not working!

### 5/5 — Excellent

*2015-04-26*

An excellent little application. I used it through my Engineering degree and it was truly helpful and more importantly, accurate. I believe it is well worth the price as there is nothing as good as this app on the App Store. The new update seems to be a nice addition to an already great app as in makes it look more appley (if that is a word). Do not hesitate about buying this application especially if you are an engineer.

### 4/5 — Practical engineering

*2014-03-02*

Great set of easy and quick use of established formula 

Hats off to Mr Hobb

### 5/5 — Nice tool

*2013-05-17*

Nice tool for mechanical engineer.

## Frequently asked questions about Moments of Inertia

### What engineering calculations does Moments of Inertia perform?

Moments of Inertia calculates key beam section properties including moments of inertia about the x & y axes, polar moment of inertia, radius of gyration, centroids, area, and section modulus.

### What geometric shapes are supported by Moments of Inertia?

Moments of Inertia supports a wide range of shapes such as Rectangles, Hollow Rectangles, Circles, Hollow Circles, Semicircles, Quarter Circles, Ellipses, Triangles, I Beams, Tee Sections, Channel Sections, and Unequal-Legged Angles.

### Can I share my calculations from Moments of Inertia?

Yes, you can easily print or email a PDF of your results. This PDF includes the cross-section schematic, inputs, equations, and calculated results.

### Does Moments of Inertia have ads?

Moments of Inertia does not contain advertisements, providing an uninterrupted user experience.

### What devices is Moments of Inertia compatible with?

Moments of Inertia is designed for use on all sizes of the iPhone, iPod Touch, and iPad.

### How often is Moments of Inertia updated?

The latest version, 2.1.5, was released on May 31, 2023, indicating regular updates to maintain functionality and compatibility.

### What is the price of Moments of Inertia?

Moments of Inertia is available for a one-time purchase of $5.99.

### What is the age rating for Moments of Inertia?

Moments of Inertia has an age rating of 4+, making it suitable for a broad audience.

## Version history (last 5 releases)

### 3.0.4 — 2026-07-07

Bug fixes and other minor updates.

### 2.1.5 — 2023-05-31

-Bug fixes
-Other minor updates

### 2.1.4 — 2020-01-21

- Bug fixes.
- Other minor updates.

### 2.1.3 — 2017-10-19

- Bug fixes
- Minor Updates

### 2.1.2 — 2017-09-20

- Updated to Latest Swift version.
- Bug fixes and other improvements.

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## More apps by J.R.Hobbs

- [Mohr's Circle](https://appshunter.io/ios/app/mohrs-circle/id395110520)
- [Pressure Vessel Pro](https://appshunter.io/ios/app/pressure-vessel-pro/id535696875)
- [Inspectix: Inspection Reports](https://appshunter.io/ios/app/inspectix-inspection-reports/id673877248)
- [Stress Intensity Factors Pro](https://appshunter.io/ios/app/stress-intensity-factors-pro/id726473168)
- [Stress Concentration Factors 2](https://appshunter.io/ios/app/stress-concentration-factors-2/id1296693579)

All apps by J.R.Hobbs: https://appshunter.io/developer/395110523

## Related topics

[inertia pro](https://appshunter.io/ios/topics/inertia-pro)

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*Data collected daily from the US App Store and indexed by [AppsHunter](https://appshunter.io/). User reviews are verbatim App Store reviews. Ratings, prices and chart positions refresh continuously; this snapshot is from 2026-09-03.*