# Custom Formulas

> User-defined equation calculator with multiple variables and functions. (iPhone/iPad app by Richard White.)

- Source: https://appshunter.io/ios/app/custom-formulas/id617617496 (this page in markdown: same URL + `.md`)
- Developer: [Richard White](https://appshunter.io/developer/523291244)
- Category: Utilities, Productivity
- Price: $0.99
- Rating: 3.00/5 from 6 App Store ratings · 6 written reviews indexed
- Age rating: 4+
- Requires: iOS 10.0 · 1 MB
- Languages: American English
- Released: 2013-03-17
- Data updated: 2026-06-10
- Monetization: paid
- User reviews in markdown: https://appshunter.io/ios/app/custom-formulas/id617617496/reviews.md

## What is Custom Formulas?

Custom Formulas allows you to store custom equations with multiple variables that you can use again and again. Unlike a lot of other apps that try to replicate a scientific calculator, Custom Formulas has been designed around the iPhone and provides a clean simple interface. All of your custom equations are available on the main launch window and with one simple click you can be entering data and getting the results you want. So what can you use it for? Well that comes down to you as Custom Formulas gives you the flexibility to create anything that you need. For example:
- Split a restaurant bill including a 15% tip
- Monthly mortgage payments
- Generate random lottery numbers from 1 to 40
- Your secret formula that you use to find the best value rental property
- Optimal firing distance for your death ray

Features
- Up to four variables can be used (and individually named)
- A good selection of functions (see below)
- Multiple levels of parentheses are supported
- Decimal place rounded supported
- A prefix & suffix can be added to the answer
- Example equations provided

Available Functions
- add
- subtract
- multiply
- divide
- square root
- random number
- power function
- int
- log 10
- cosine
- sine
- tangent

## Key features

- Store custom equations with multiple variables
- Clean and simple interface
- Equations available on main launch window
- Up to four named variables per equation
- Supports multiple levels of parentheses
- Decimal place rounding
- Prefix and suffix for answers

## Recent user reviews (6 of 6)

All indexed reviews: https://appshunter.io/ios/app/custom-formulas/id617617496/reviews.md

### 5/5 — Only 4 variables, but works great!

*2023-07-31*

Very cool app. Just get your equation whittled down to 4 variables.

### 2/5 — Weak

*2022-11-08, version 1.3*

Four variable maximum? My 1988 sixth grade desktop with 4 mb of ram had more flexibility

### 5/5 — Excellent!

*2018-10-30, version 1.1*

This is a nice little app; is is just what i wanted.

Use the “Edit” button to create/edit/delete existing and/or new formulas. 

Simple and easy to set up custom formulas; i like it!

### 1/5 — Limited

*2018-02-28, version 1.1*

Cannot add more Formulas than what was there.  Waste of money.

### 1/5 — Character limit not advertised

*2015-06-04, version 1.0*

I bought this app to perform a long (~120 char) but often repeated formula that uses two changing variables. Apparently there is an 80 character limit that is not mentioned anywhere in the description. I am disappointed.

If I knew this ahead of time, I wouldn't have bought this app. If this limit is raised or removed later on, I will change my review.

### 5/5 — Great app

*2014-04-29, version 1.0*

Great app to use for custom formulas with up to 4 variables. Easy to use and let's you label each variable. Now I don't have to type in long calc problems for work or open excell all the time either.

## Frequently asked questions about Custom Formulas

### What is Custom Formulas?

Custom Formulas is a paid utility app that allows you to create and save your own equations with multiple variables. It provides a clean interface for quick calculations and results, designed specifically for iPhone users.

### How many variables can Custom Formulas handle?

Each custom equation in Custom Formulas can utilize up to four variables, and each of these variables can be individually named for clarity and ease of use.

### What kind of functions are available in Custom Formulas?

The app includes a selection of basic arithmetic functions (add, subtract, multiply, divide), as well as more advanced functions like square root, random number generation, power, integer conversion, log 10, cosine, sine, and tangent.

### Can I use Custom Formulas offline?

The description does not specify offline functionality, but as a calculator app, it is likely designed to work without an internet connection once installed.

### What devices does Custom Formulas support?

Custom Formulas is available for iPhone and iPod devices. It was last updated on February 4, 2019, with version 1.3.

### What is the age rating for Custom Formulas?

Custom Formulas has an age rating of 4+, making it suitable for a wide range of users. The app was first released on March 17, 2013.

### How much does Custom Formulas cost?

Custom Formulas is a paid application priced at $0.99. There are no mentions of in-app purchases or subscriptions.

### What is the user sentiment for Custom Formulas based on ratings?

The app has a rating of 3.0 stars from 6 ratings. This suggests a mixed reception from its user base.

## Version history (last 4 releases)

### 1.3 — 2019-02-04

- Added the option to use Log 10 functionality in your equations
- Some minor bug fixes

### 1.2 — 2018-11-12

- Added the ability to add a suffix to the answer
- Several layout and stability issues fixed

### 1.1 — 2016-03-04

- Added a new INT function
- Added the ability to add a prefix to the answer
- If required the answer can now be rounded to 0, 1 or 2 decimal places
- Several layout and stability issues fixed

### 1.0 — 2013-03-17

No release notes.

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## More apps by Richard White

- [Corporate King](https://appshunter.io/ios/app/corporate-king/id1545694211)

All apps by Richard White: https://appshunter.io/developer/523291244

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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.*