# Custom Formulas vs CalcFlex

The clearest difference is price: CalcFlex at Free against Custom Formulas's $3.99. Custom Formulas's advantage is in-app purchases (none vs 6) and chart position (#186 vs unranked). On update cadence and ads there is nothing between them.

CalcFlex is free to download; Custom Formulas costs $3.99 up front. CalcFlex sells 3 one-off in-app purchases. Custom Formulas asks for nothing beyond the download.

Custom Formulas ships an update every 5 days, CalcFlex every 9 days. The most recent releases landed on September 18, 2026 and September 19, 2026 respectively.

## The numbers

| Metric | Custom Formulas | CalcFlex |
| --- | --- | --- |
| Price | $3.99 | **Free** |
| Rating | **[5.0 (1 ratings)](https://appshunter.io/ios/app/custom-formulas/id1623368630/reviews)** | — |
| Number of ratings | **1** | — |
| Positive reviews | 100.0% of reviews | — |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | **Every 5 days** | Every 9 days |
| Monetization | Paid | — |
| Best chart rank | **#186** | — |
| Size | 1 MB | 2 MB |
| Requires iOS | **15.4** | 17.0 |
| Devices | **iPhone, iPad, iPod** | iPhone |
| Age rating | 4+ | 4+ |
| Developer | [Anthony Dunk](https://appshunter.io/developer/704471943) | [Daniel Chiu Loong Ng](https://appshunter.io/developer/1755978644) |

## What reviewers say

### Custom Formulas

[App page](https://appshunter.io/ios/app/custom-formulas/id1623368630)

**Currently charting:** #186 Top Paid · Utilities (US App Store)

This utility app allows users to create and manage complex calculations with multiple inputs and outputs. Formulas can be linked, grouped into categories, and customized for display precision. Share your custom calculations easily via email.

**Highlights:** Multiple input/output formula support, Linked formulas via variable names, Formula categorization, Customizable variable display order, Adjustable output decimal precision, Email formula sharing

**Features:** macOS Compatibility, Vision Pro support

**In-app purchases:** none


### CalcFlex

[App page](https://appshunter.io/ios/app/calcflex-calculator/id6520389768)

**In-app purchases (3)**

| Purchase | Price | Billing |
| --- | --- | --- |
| +3 New Variables | $1.99 | one-time |
| +20 New Equation Slots | $1.99 | one-time |
| +1 New Calculator | $3.99 | one-time |


## Frequently asked questions

### Is Custom Formulas free?

Custom Formulas costs $3.99, with no in-app purchases.

### Is CalcFlex free?

CalcFlex is free to download, with in-app purchases available.

### Do Custom Formulas or CalcFlex have ads?

Neither Custom Formulas nor CalcFlex shows ads.

### Which is updated more often, Custom Formulas or CalcFlex?

Custom Formulas ships an update every 5 days, and CalcFlex every 9 days. Most recently, Custom Formulas was updated on September 18, 2026 and CalcFlex on September 19, 2026.

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*Compared by [AppsHunter](https://appshunter.io/) from daily US App Store data. Review summaries are generated from verbatim App Store reviews.*