# Ultimate Slide Rule

> Digital slide rule app with multiple scales and interactive learning guides. (iPhone/iPad app by Rowan Richards.)

- Source: https://appshunter.io/ios/app/ultimate-slide-rule/id6636523467 (this page in markdown: same URL + `.md`)
- Developer: [Rowan Richards](https://appshunter.io/developer/1762971026)
- Category: Education, Utilities
- Price: $0.99 with in-app purchases
- Rating: 4.90/5 from 9 App Store ratings · 5 written reviews indexed
- Age rating: +4
- Requires: iOS 17.0 · 7 MB
- Languages: American English
- Released: 2024-08-15
- Data updated: 2026-09-06
- Monetization: paid
- User reviews in markdown: https://appshunter.io/ios/app/ultimate-slide-rule/id6636523467/reviews.md

## What is Ultimate Slide Rule?

The Ultimate Slide Rule brings the classic analog calculator into a sleek digital format.

Whether you're a student, engineer, or enthusiast, the Ultimate Slide Rule is your go-to tool for mastering and remembering the timeless art of slide rule calculations.


Key Features:

Multiple Scales: Access nearly two dozen unique measurement scales to perform calculations ranging from multiplication to trigonometry, exponents, and logarithms.

Interactive Learning Guides: More than just a tool, the Ultimate Slide Rule is a comprehensive learning device, featuring more than a dozen immersive guides that teach you how to use a slide rule effectively.

Intuitive Interface: Easily navigate complex calculations with just a few swipes, replicating the traditional slide rule experience with modern convenience.

Compact and Convenient: Carry the power of a full 12'' slide rule in your pocket, perfect for impressing friends or solving problems on the go.

## Key features

- Multiple measurement scales
- Interactive learning guides
- Intuitive swipe interface
- Pocket-sized convenience
- Trigonometry, exponents, logarithms

## Pricing and in-app purchases

Base price: $0.99.

**One-time purchases**

| Purchase | Price | Type |
| --- | --- | --- |
| Slide Rule Enthusiast | $0.99 | one-time |
| Slide Rule Connoisseur | $9.99 | one-time |
| Slide Rule Supporter | $1.99 | one-time |
| Slide Rule Advocate | $4.99 | one-time |


## Chart rankings

- #200 in Top Paid · Education (US App Store)

## Recent user reviews (5 of 5)

All indexed reviews: https://appshunter.io/ios/app/ultimate-slide-rule/id6636523467/reviews.md

### 5/5 — Excellent usability

*2025-09-14*

This app implements a slide rule very well and its usability is excellent. Zoom and reversals are intuitive and pleasant to use.
The scale arrangement (especially the LL scales) are a bit unusual, but this is secondary to demonstrating the principles of the slide rule.

**Developer response:** Hi, Im glad you liked the slide rule. Im not much of an expert on the subject, so the scale layout was copied directly from a real slide rule I own. Sorry if it caused any confusion.

### 5/5 — Usable and educational

*2025-04-30*

It’s cleverly designed so you can actually use it from your phone. 

It includes integrated tutorials which actually teach you how to use a slide rule. 

Haven’t found any other SOS which do the same. Is great!

### 4/5 — Index adjust

*2025-01-21*

Consider index tap adjust similar to the hairline home.  Love how the hairline centers with tap.

### 5/5 — Amazing App, Minuscule Error

*2024-12-19*

I loved the amazing functionality of this app. Virtually every calculation can be accomplished with the high accuracy and precision of the scales provided. However, I have noticed an error in the markings on the left side of LL2. Although the tick marks for 1.11 and 1.2 are placed correctly, the tick marks in between and the label of 1.15 are inaccurately placed. Other than this caveat, the slide rule is amazing as well as visually pleasing. The simple design with a well-thought-out color palette make the app pleasing to the eye. Additionally, the zooming and locate cursor functions make the app more accessible and ergonomic. I would highly recommend this app, but please fix the tick mark placement on LL2.

**Developer response:** Hello. Im glad you’re enjoying the app. I see what you’re referring to with the LL2 scale and I’ll try to fix it in the next update. Thanks for pointing it out.

### 5/5 — Best app ever

*2024-10-13*

This is a great app! Not a fault I can find. No ads! The rule is gorgeous and, unlike actual slide rules, very easy for me to see. You can even zoom in. 
My son is getting married today and I was trying to figure out last night during set-up if we had enough places sat for guests expected. I opened up the calculator app on my phone then thought “wait! I’ll use my slide rule app!”

## Frequently asked questions about Ultimate Slide Rule

### What is the Ultimate Slide Rule app?

The Ultimate Slide Rule app digitizes the classic analog slide rule, providing a convenient tool for performing calculations. It features multiple scales and interactive guides to teach users how to use it effectively.

### What kind of calculations can I do with the Ultimate Slide Rule?

You can perform a wide range of calculations, including multiplication, division, trigonometry, exponents, and logarithms, using nearly two dozen unique measurement scales.

### Is the Ultimate Slide Rule good for learning?

Yes, it includes over a dozen immersive guides designed to teach you how to use a slide rule effectively, making it a comprehensive learning device.

### What devices does the Ultimate Slide Rule support?

Currently, the Ultimate Slide Rule is supported on iPhone devices.

### How much does the Ultimate Slide Rule cost?

The Ultimate Slide Rule is a paid app, available for $0.99.

### How often is the Ultimate Slide Rule updated?

The app was last updated on March 3, 2025, indicating regular maintenance and potential feature additions.

### What is the age rating for the Ultimate Slide Rule?

The Ultimate Slide Rule has an age rating of 4+, making it suitable for a wide range of users.

### Does the Ultimate Slide Rule have ads?

No, the Ultimate Slide Rule is ad-free, providing an uninterrupted user experience.

## Version history (last 4 releases)

### 1.3 — 2025-03-03

Overhauled Tutorials
-More visuals
-Custom inputs
    -Shows you how to evaluate any expression
-More descriptions for certain confusing steps
-Step list
-Auto completion

Better zooming
-Ability to zoom out more
-Zooming is easier to interact with

Haptic feedback for some actions

Bug fixes
-LL2 scale tick marks now display properly
-Cursor centering now accounts for zoom

### 1.2 — 2024-11-15

Revamped Icons

Settings
- App Info
- Support
- Slow down motion when zoomed in
- Fun Zone
-- Physics

Added pi and e constants to C and D scales

Added scale labels on the side of the screen for convenience

Fixed display bug on some devices

### 1.1 — 2024-08-23

UI fixes

### 1.0 — 2024-08-15

No release notes.

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## Related topics

[smart slide rule](https://appshunter.io/ios/topics/smart-slide-rule) · [super cool slide rule](https://appshunter.io/ios/topics/super-cool-slide-rule) · [slide rule](https://appshunter.io/ios/topics/slide-rule) · [pocket slide rule expert](https://appshunter.io/ios/topics/pocket-slide-rule-expert)

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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 2026-09-06.*