# Resistor Tools Pro vs RMS Calculator

The clearest difference is update cadence: Resistor Tools Pro at every 2 months against RMS Calculator's every 15 months. Resistor Tools Pro also leads on price ($0.99 vs $1.99). On ads, in-app purchases, device support and iOS requirement there is nothing between them.

Resistor Tools Pro costs $0.99 and RMS Calculator $1.99 up front. Neither carries in-app purchases, so what you see is what you pay.

Resistor Tools Pro ships an update every 2 months, RMS Calculator every 15 months. The most recent releases landed on October 21, 2026 and October 25, 2026 respectively.

## The numbers

| Metric | Resistor Tools Pro | RMS Calculator |
| --- | --- | --- |
| Price | **$0.99** | $1.99 |
| Rating | **[4.0 (1 ratings)](https://appshunter.io/ios/app/resistor-tools-pro/id825620924/reviews)** | — |
| Number of ratings | **1** | — |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | **Every 2 months** | Every 15 months |
| Monetization | Paid | — |
| Size | 4 MB | 8 MB |
| Requires iOS | 12.0 | 12.0 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | +4 |
| Developer | [Siu Yuen Ho](https://appshunter.io/developer/814088527) | [Kei Suefuji](https://appshunter.io/developer/1388335881) |

## 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


### RMS Calculator

[App page](https://appshunter.io/ios/app/rms-calculator/id1511092361)

**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 RMS Calculator free?

RMS Calculator costs $1.99, with no in-app purchases.

### Do Resistor Tools Pro or RMS Calculator have ads?

Neither Resistor Tools Pro nor RMS Calculator shows ads.

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

Resistor Tools Pro ships an update every 2 months, and RMS Calculator every 15 months. Most recently, Resistor Tools Pro was updated on October 21, 2026 and RMS Calculator on October 25, 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.*