# Resistor Tools Pro vs Transformer Calculator Plus

The clearest difference is rating: Resistor Tools Pro at 4.0 against Transformer Calculator Plus's 3.3. Resistor Tools Pro also leads on update cadence (every 2 months vs every 45 months) and price ($0.99 vs $2.99). Transformer Calculator Plus's advantage is ratings volume (4 vs 1). On ads, in-app purchases, monetization model and device support there is nothing between them.

Resistor Tools Pro costs $0.99 and Transformer Calculator Plus $2.99 up front. Neither carries in-app purchases, so what you see is what you pay.

Resistor Tools Pro holds the better App Store score, 4.0 against 3.3. Both are backed by a comparable volume of ratings — 1 and 4 respectively.

Resistor Tools Pro ships an update every 2 months, Transformer Calculator Plus every 45 months. The most recent releases landed on June 25, 2026 and September 10, 2026 respectively.

## The numbers

| Metric | Resistor Tools Pro | Transformer Calculator Plus |
| --- | --- | --- |
| Price | **$0.99** | $2.99 |
| Rating | **[4.0 (1 ratings)](https://appshunter.io/ios/app/resistor-tools-pro/id825620924/reviews)** | [3.3 (4 ratings)](https://appshunter.io/ios/app/transformer-calculator-plus/id1372528401/reviews) |
| Number of ratings | 1 | **4** |
| Positive reviews | — | 0.0% of reviews |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | **Every 2 months** | Every 45 months |
| Monetization | Paid | Paid |
| Size | 4 MB | 1 MB |
| Requires iOS | **12.0** | 13.0 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Siu Yuen Ho](https://appshunter.io/developer/814088527) | [Nitrio](https://appshunter.io/developer/321121189) |

## What reviewers say

### Resistor Tools Pro

[App page](https://appshunter.io/ios/app/resistor-tools-pro/id825620924)

This utility app offers a suite of tools for calculating and finding resistor combinations. It's designed for electronics enthusiasts and professionals needing to determine series, parallel, and voltage divider configurations. Save and share your calculations easily.

**Highlights:** Calculate series/parallel resistance, Find resistor combinations for desired resistance, Voltage divider ratio and value calculation, Inverting amplifier gain calculation, Save combinations to CSV, Share via AirDrop, Upload CSV to iCloud Drive

**In-app purchases:** none


### Transformer Calculator Plus

[App page](https://appshunter.io/ios/app/transformer-calculator-plus/id1372528401)

This utility app calculates key parameters for transformers, including voltage, current, and turns ratio. It helps determine if a transformer is step-up or step-down, essential for power conversion applications.

**Highlights:** Calculate primary and secondary voltage, Calculate primary and secondary current, Calculate transformer turns ratio, Determine step-up or step-down transformer, Supports AC voltage calculations

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

**In-app purchases:** none


## Frequently asked questions

### Is Resistor Tools Pro free?

Resistor Tools Pro costs $0.99, with no in-app purchases.

### Is Transformer Calculator Plus free?

Transformer Calculator Plus costs $2.99, with no in-app purchases.

### Which has better reviews, Resistor Tools Pro or Transformer Calculator Plus?

Resistor Tools Pro is rated higher. Resistor Tools Pro averages 4.0 out of 5 from 1 ratings, while Transformer Calculator Plus averages 3.3 from 4 ratings.

### Do Resistor Tools Pro or Transformer Calculator Plus have ads?

Neither Resistor Tools Pro nor Transformer Calculator Plus shows ads.

### Which is updated more often, Resistor Tools Pro or Transformer Calculator Plus?

Resistor Tools Pro ships an update every 2 months, and Transformer Calculator Plus every 45 months. Most recently, Resistor Tools Pro was updated on June 25, 2026 and Transformer Calculator Plus on September 10, 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.*