# Radius Calculator

> Calculates arc segment properties from span and rise with unit conversion. (iPhone/iPad app by MaoWare Corporation.)

- Source: https://appshunter.io/ios/app/radius-calculator/id453210969 (this page in markdown: same URL + `.md`)
- Developer: [MaoWare Corporation](https://appshunter.io/developer/383841907)
- Category: Business, Utilities
- Price: $1.99
- Rating: 4.80/5 from 63 App Store ratings · 7 written reviews indexed
- Age rating: 4+
- Requires: iOS 10.0 · 21 MB
- Languages: American English
- Released: 2011-08-04
- Data updated: 2026-06-10
- Monetization: paid
- User reviews in markdown: https://appshunter.io/ios/app/radius-calculator/id453210969/reviews.md

## What is Radius Calculator?

Radius Calculator allows you to calculate the radius, central angle, arc length, and circumference from the span / chord and rise of an arc segment.  Built-in unit converter makes it to work with any length unit (including inches, feet, centimeters, meters, and many more).

Simply enter the span / chord and the rise to arc in your choice of units.  Then pick the output unit unit and the radius, central angle, arc length, and circumference are instantly computed.

Designed for the multiple trades in the construction industry, this calculator is great for any craftsman who needs to find properties of a circle given curve measurements.  In particular, Radius Calculator is perfect carpenters or cabinet makers who deal with curved walls.

Note: There is no closed form solution for the central angle and we use a common approximation for that calculation.  This method is very accurate for small angles and about 10% off on large angles approaching 180 degrees.

## Key features

- Calculate radius
- Calculate central angle
- Calculate arc length
- Calculate circumference
- Built-in unit converter
- Supports multiple length units

## Recent user reviews (7 of 7)

All indexed reviews: https://appshunter.io/ios/app/radius-calculator/id453210969/reviews.md

### 3/5 — X /2) / (y*2) + (y/2) = R

*2022-07-10*

Not bad but it would be better if you could type in 
Fraction  up to 32s  at least

### 5/5 — Awesome

*2018-09-17*

Awesome app . Best thing since sliced bread!

### 5/5 — Incredibly Useful and Efficient

*2017-10-14*

I do a lot of radius woodwork.  This app saves me from waiting until I get back to my desk to figure out the radius of whatever project I'm producing.
I recommend this to anyone in construction.  It surely has other uses as well for other trades.

### 2/5 — Very, very basic app

*2017-02-05*

There are no settings and no graphical representation - all you get is a table with 2 input fields for width and elevation and it gives you 4 results in your selected units.
Very, very basic app.
The description refers to the calculated "centre angle" being an estimate - but it does not provide a definition or any identification of what they are calling the "centre angle". 
I expected more, even if this were a free app I would still feel disappointed.

### 3/5 — Ok app

*2013-03-22*

Would be nice if it would stop defaulting to inches

### 1/5 — Inaccurate

*2012-02-22*

This app is inaccurate. I don't know what the general contractor was thinking when he used it to hang a garage door. He needs to check it because it had me off by 8 inches. I had to log on to handy math just to get the right arc length. When you calculate the height being half the span it gives you a central angle of 160.bs. Maybe on Mars but on earth it's 180. Don't waste your money!

### 5/5 — Great Arc App

*2011-08-05*

I am a general contractor and was trying to figure out the radius of the arc over a garage door header, I downloaded the app and had the radius in about one minute. It would of taken me 20 min to figure it out! 1.99 app saved me about $ 12 in labor.

## Frequently asked questions about Radius Calculator

### What is the price of Radius Calculator?

Radius Calculator is a paid app priced at $1.99. This one-time purchase grants you access to all its features for calculating arc segment properties.

### Does Radius Calculator have ads?

No, Radius Calculator does not contain advertisements. As a paid application, it offers an ad-free experience for users.

### On which devices can I use Radius Calculator?

Radius Calculator is available for iPhone, iPad, and iPod touch devices. Its interface is designed to be compatible with Apple's mobile ecosystem.

### How accurate is the central angle calculation in Radius Calculator?

The app uses a common approximation for the central angle calculation. This method is highly accurate for small angles but may be up to 10% off for larger angles approaching 180 degrees.

### What units does Radius Calculator support?

Radius Calculator supports a wide range of length units, including inches, feet, centimeters, and meters, thanks to its built-in unit converter. You can input measurements in one unit and receive calculations in another.

### When was Radius Calculator last updated?

The latest version of Radius Calculator was released on November 29, 2018. While the app was initially released in 2011, this update indicates ongoing maintenance.

### What is the age rating for Radius Calculator?

Radius Calculator has an age rating of 4+. This indicates it is suitable for users of all ages and does not contain content inappropriate for children.

### What do users like about Radius Calculator?

Users appreciate Radius Calculator's functionality and ease of use, contributing to its high rating of 4.8 stars from 63 ratings. The built-in unit converter is a frequently praised feature for its convenience.

## Version history (last 5 releases)

### 7.0.0 — 2018-11-29

- iOS 12 support
- iPhone XR/XS/XS Max support

### 6.0.0 — 2017-11-10

- iOS 11 support
- iPhone X support

### 5.0.0 — 2017-01-30

- iOS 10 support
- iPhone 7 support

### 4.0.0 — 2016-06-20

- iOS 9 support
- iPhone 6s / iPad Pro support

### 3.0.0 — 2014-11-08

- iOS 7 / 8 support
- iPhone 6 / iPhone 6 Plus support

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## More apps by MaoWare Corporation

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- [Molarity Calculator](https://appshunter.io/ios/app/molarity-calculator/id448142561)
- [Easy Square Calculator](https://appshunter.io/ios/app/easy-square-calculator/id449511334)

All apps by MaoWare Corporation: https://appshunter.io/developer/383841907

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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 2026-06-10.*