# Formula Conversion vs CalculateVolumePro

The clearest difference is update cadence: CalculateVolumePro at weekly against Formula Conversion's every 26 months. Formula Conversion's advantage is iOS requirement (14.1 vs 18.0). On price, ads, in-app purchases and device support there is nothing between them.

Both are free to download. Formula Conversion sells 1 one-off in-app purchase and CalculateVolumePro sells 1 one-off in-app purchase. Whichever you choose, the download price is not the number that matters.

Formula Conversion ships an update every 26 months, CalculateVolumePro weekly. The most recent releases landed on October 14, 2026 and October 4, 2026 respectively.

## The numbers

| Metric | Formula Conversion | CalculateVolumePro |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | Yes | Yes |
| Ads | No | No |
| Update frequency | Every 26 months | **Weekly** |
| Size | 2 MB | 3 MB |
| Requires iOS | **14.1** | 18.0 |
| Devices | **iPhone, iPad, iPod** | iPhone, iPad |
| Age rating | 4+ | 4+ |
| Developer | [Janek Soomets](https://appshunter.io/developer/1315295062) | [Maxime Haeyaert](https://appshunter.io/developer/1274130669) |

## What reviewers say

### Formula Conversion

[App page](https://appshunter.io/ios/app/formula-conversion/id1586539965)

**Features:** macOS Compatibility

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Upgrade Formula Conversion | $3.99 | one-time |


### CalculateVolumePro

[App page](https://appshunter.io/ios/app/calculatevolumepro/id6737241011)

**Features:** macOS Compatibility

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Detailed calculations | $0.99 | one-time |


## Frequently asked questions

### Is Formula Conversion free?

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

### Is CalculateVolumePro free?

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

### Do Formula Conversion or CalculateVolumePro have ads?

Neither Formula Conversion nor CalculateVolumePro shows ads.

### Which is updated more often, Formula Conversion or CalculateVolumePro?

Formula Conversion ships an update every 26 months, and CalculateVolumePro weekly. Most recently, Formula Conversion was updated on October 14, 2026 and CalculateVolumePro on October 4, 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.*