# Inductor Design Pro vs Calculation Transformers

The clearest difference is update cadence: Inductor Design Pro at every 3 weeks against Calculation Transformers's every 5 months. Calculation Transformers's advantage is iOS requirement (13.0 vs 15.0). On price, ads, in-app purchases and device support there is nothing between them.

Both are free to download. Inductor Design Pro sells 1 in-app purchase, starting at $29.99 per year and Calculation Transformers sells 1 one-off in-app purchase. Whichever you choose, the download price is not the number that matters.

Inductor Design Pro ships an update every 3 weeks, Calculation Transformers every 5 months. The most recent releases landed on July 4, 2026 and September 17, 2026 respectively.

## The numbers

| Metric | Inductor Design Pro | Calculation Transformers |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | Yes | Yes |
| Ads | No | No |
| Update frequency | **Every 3 weeks** | Every 5 months |
| Size | 9 MB | 56 MB |
| Requires iOS | 15.0 | **13.0** |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [建忠 徐](https://appshunter.io/developer/1871049057) | [Nanjibhai Gorasiya](https://appshunter.io/developer/1834066312) |

## What reviewers say

### Inductor Design Pro

[App page](https://appshunter.io/ios/app/inductor-design-pro/id6758878884)

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Annual Subscription | $29.99 | per year |


### Calculation Transformers

[App page](https://appshunter.io/ios/app/calculation-transformers/id6759037556)

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

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Lifetime premium | $9.99 | one-time |


## Frequently asked questions

### Is Inductor Design Pro free?

Inductor Design Pro is free to download, with in-app purchases available.

### Is Calculation Transformers free?

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

### Do Inductor Design Pro or Calculation Transformers have ads?

Neither Inductor Design Pro nor Calculation Transformers shows ads.

### Which is updated more often, Inductor Design Pro or Calculation Transformers?

Inductor Design Pro ships an update every 3 weeks, and Calculation Transformers every 5 months. Most recently, Inductor Design Pro was updated on July 4, 2026 and Calculation Transformers on September 17, 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.*