# Resistor Tools

> Electronic resistor calculation and combination tools for hobbyists and engineers. (iPhone/iPad app by Siu Yuen Ho.)

- Source: https://appshunter.io/ios/app/resistor-tools/id826045228 (this page in markdown: same URL + `.md`)
- Developer: [Siu Yuen Ho](https://appshunter.io/developer/814088527)
- Category: Utilities
- Price: Free with in-app purchases
- Rating: 5.00/5 from 10 App Store ratings · 4 written reviews indexed
- Age rating: 4+
- Requires: iOS 12.0 · 4 MB
- Languages: French (France), German (Germany), American English, Chinese (Simplified, China), Chinese (Traditional, Taiwan), European Spanish, Hindi, Italian, Japanese, European Portuguese and 1 more
- Released: 2014-02-28
- Data updated: 2026-08-28
- Monetization: free with in-app purchases
- User reviews in markdown: https://appshunter.io/ios/app/resistor-tools/id826045228/reviews.md

## What is Resistor Tools?

This app is a collection of resistor calculators. It is suitable for hobbyist or electronic engineer.

* Calculate resistance of two resistors in series or parallel
* Find out combinations of two resistors in series/parallel making a desired resistance
* Calculate ratio of R1/R2 and voltage divider
* Find out resistor values of making voltage divider ratio
* Find out resistor values of making inverting amplifier gain
* Save combination values in CSV file

## Key features

- Series and parallel resistor calculation
- Resistor combination finder
- Voltage divider ratio and value calculation
- Inverting amplifier gain calculation
- Save combinations to CSV

## Pricing and in-app purchases

Base price: Free.

**One-time purchases**

| Purchase | Price | Type |
| --- | --- | --- |
| Unlock pro feature | $0.99 | one-time |


## Recent user reviews (4 of 4)

All indexed reviews: https://appshunter.io/ios/app/resistor-tools/id826045228/reviews.md

### 5/5 — Ajuda muito

*2025-07-28*

Simples e bem feito.

### 2/5 — In Voltage divider R1 & R2 is reversed position.

*2022-08-22*

In Voltage divider R1 & R2 is reversed position.

### 5/5 — Works

*2017-05-14*

It's free and it works. Can't ask for more really

### 5/5 — Nice

*2015-07-23*

Good!!

## Frequently asked questions about Resistor Tools

### What can Resistor Tools calculate?

Resistor Tools can calculate the resistance of two resistors in series or parallel, find combinations that make a desired resistance, calculate voltage divider ratios and resistor values, and determine resistor values for inverting amplifier gain.

### Can I save my resistor calculations with Resistor Tools?

Yes, Resistor Tools allows you to save your combination values in a CSV file, making it easy to export and reference your calculations.

### Is Resistor Tools free to use?

Resistor Tools is free to download and use. It also offers in-app purchases, which may provide additional features or functionality.

### What devices does Resistor Tools support?

Resistor Tools is available for iPhone, iPad, and iPod devices, making it accessible to a wide range of Apple users.

### How often is Resistor Tools updated?

The latest version of Resistor Tools was released on March 26, 2024, indicating active development and regular updates to the application.

### What is the age rating for Resistor Tools?

Resistor Tools has an age rating of 4+, meaning it is suitable for users of all ages and does not contain mature content.

### How does Resistor Tools compare to other electronics calculators?

Resistor Tools offers a focused set of tools specifically for resistor calculations, including series, parallel, voltage divider, and amplifier gain. Its high rating suggests a positive user experience for these specific functions.

### Does Resistor Tools have ads?

Resistor Tools does not contain advertisements, providing an uninterrupted user experience for its calculations and tools.

## Version history (last 5 releases)

### 2.6.30 — 2024-03-26

Fix minor bugs

### 2.6.25 — 2022-03-04

* Support German, French, Italian, Spanish, Portuguese, Japanese, Russian and Hindi

### 2.6.10 — 2022-02-21

* Calculate resistance of n resistors in series  
* Calculate resistance of n resistors in parallel

### 2.5.0 — 2020-02-25

Fix minor bug

### 2.4.1 — 2019-12-30

- Fix minor bugs

## Apps similar to Resistor Tools

| App | Rating | Price | Category |
| --- | --- | --- | --- |
| [Resistor Code Calculators](https://appshunter.io/ios/app/resistor-code-calculators/id1465336419) | — | Free | Utilities |
| [Electrical Series Calculator](https://appshunter.io/ios/app/electrical-series-calculator/id967967501) | 4.5 (13) | Free | Utilities |
| [Voltage Divider Calculator](https://appshunter.io/ios/app/voltage-divider-calculator/id6505137107) | 3.3 (3) | Free | Utilities |
| [SMD decoder](https://appshunter.io/ios/app/smd-decoder/id6473452077) | 5.0 (1) | Free | Utilities |
| [Resistor-Converter](https://appshunter.io/ios/app/resistor-converter/id6446839759) | 4.9 (17) | Free | Utilities |
| [Resistor AI Calculator](https://appshunter.io/ios/app/resistor-ai-calculator/id1587462977) | 3.6 (5) | Free | Utilities |

## More apps by Siu Yuen Ho

- [Easy Ohm's Law](https://appshunter.io/ios/app/easy-ohms-law/id814088524)
- [RC Circuit Pro](https://appshunter.io/ios/app/rc-circuit-pro/id824145786)
- [RC Circuit](https://appshunter.io/ios/app/rc-circuit/id824460716)
- [Resistor Tools Pro](https://appshunter.io/ios/app/resistor-tools-pro/id825620924)
- [Timer 555 Calculator Pro](https://appshunter.io/ios/app/timer-555-calculator-pro/id833443125)

All apps by Siu Yuen Ho: https://appshunter.io/developer/814088527

## Related topics

[resistor tools](https://appshunter.io/ios/topics/resistor-tools) · [resistor tools pro](https://appshunter.io/ios/topics/resistor-tools-pro) · [voltage divider](https://appshunter.io/ios/topics/voltage-divider) · [smd resistor](https://appshunter.io/ios/topics/smd-resistor)

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*Data collected daily from the US App Store and indexed by [AppsHunter](https://appshunter.io/). User reviews are verbatim App Store reviews. Ratings, prices and chart positions refresh continuously; this snapshot is from 2026-08-28.*