# Resistor Plus — Resistor Calculator

> Resistor color code calculator for determining resistance and tolerance. (iPhone/iPad app by Nitrio.)

- Source: https://appshunter.io/ios/app/resistor-plus/id500615686 (this page in markdown: same URL + `.md`)
- Developer: [Nitrio](https://appshunter.io/developer/321121189)
- Category: Education, Utilities
- Price: $2.99
- Age rating: 4+
- Requires: iOS 16.6 · 1 MB
- Languages: American English
- Released: 2012-02-13
- Data updated: 2026-08-15
- Monetization: paid
- User reviews in markdown: https://appshunter.io/ios/app/resistor-plus/id500615686/reviews.md

## What is Resistor Plus?

Resistor Calculator is the essential tool for electronics engineers, hobbyists, makers, and students. Instantly decode resistor color bands, calculate circuit values, and look up standard resistor values — all in one app.

RESISTOR COLOR CODE CALCULATOR
• Support for 4-band, 5-band, and 6-band resistors
• Tap color bands on a realistic resistor graphic to read values instantly
• View resistance, tolerance, min/max range, and temperature coefficient
• Intuitive color picker with all standard EIA color codes

REVERSE LOOKUP
• Enter a resistance value and get the matching color band combination
• Find the closest standard value from E-series tables
• Perfect for designing circuits and selecting components

SERIES & PARALLEL CALCULATOR
• Calculate total resistance for resistors in series or parallel
• Add unlimited resistors with engineering notation input (e.g. 4.7k, 2.2M)
• See live results with formula reference

VOLTAGE DIVIDER
• Solve for output voltage (Vout) or unknown resistor (R2)
• Interactive circuit diagram updates in real time
• Supports engineering notation for quick input

E-SERIES REFERENCE LIBRARY
• Browse standard resistor values from E12, E24, E48, E96, and E192 series
• Search and filter values instantly
• Tap to copy any value to clipboard

DESIGNED FOR ENGINEERS
• Clean, distraction-free interface
• Works on iPhone and iPad
• No ads, no subscriptions, no internet required
• Haptic feedback for a responsive experience

Whether you are building your first LED circuit or designing professional PCBs, Resistor Calculator Pro gives you fast, accurate answers right on your device. Download now and keep the most useful resistor tool in your pocket.

Resistor Parameters:
Band Digit
Black - 0
Brown - 1
Red - 2
Orange - 3
Yellow - 4
Green - 5
Blue - 6
Violet - 7
Grey - 8
White - 9

Band Multiplier
Black × 1 Ω 
Brown × 10 Ω
Red × 100 Ω
Orange × 1 kΩ
Yellow × 10 kΩ
Green × 100 kΩ
Blue × 1 MΩ
Violet × 10 MΩ
Gold × 0.1 Ω
Silver × 0.01 Ω

Band Tolerance
Brown - 1%
Red - 2%
Gold - 5%
Silver - 10%

A resistor is a passive two-terminal electrical component that implements electrical resistance as a circuit element. In electronic circuits, resistors are used to reduce current flow, adjust signal levels, divide voltages, bias active elements, and terminate transmission lines, among other uses. A resistor opposes the flow of electrical current; the higher the value of the resistor, the more it opposes the current flow. Values are given in ohms.

Thank you for your support! Visit nitrio.com for more apps for your iOS devices.

## Key features

- Resistor color code calculation
- Tolerance calculation
- Instant results display
- Copy result functionality
- Screenshot capability
- Works on iPhone and iPad
- Ad-free and private

## Recent user reviews (3 of 3)

All indexed reviews: https://appshunter.io/ios/app/resistor-plus/id500615686/reviews.md

### 1/5 — Worthless

*2019-08-23*

Paid money for an app that doesn’t even run. I have an iPhone X. I will be looking into getting my money back

### 1/5 — Does not work

*2016-04-29*

Beware..!! This app does not work. Just shows a blank screen.

### 1/5 — Does not work

*2014-12-15*

Loads to a black screen and nothing there...
Can't get support...
Had to buy a competitors app because I needed something that would work right away...
Very disappointed😰

## Frequently asked questions about Resistor Plus

### How do I use Resistor Plus to find a resistor's value?

To use Resistor Plus, tap to select the color values for each resistor band. The app will immediately display the calculated resistance in ohms and its tolerance.

### What devices does Resistor Plus support?

Resistor Plus works seamlessly on both iPhone and iPad devices, offering a consistent experience across Apple's mobile platforms.

### Is Resistor Plus free to download?

No, Resistor Plus is a paid application. It is available for a one-time purchase price of $2.99.

### Does Resistor Plus have ads?

No, Resistor Plus is ad-free. The app was built with privacy in mind and does not contain any advertisements.

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

Yes, you can take a screenshot of the resistor value and color code displayed in the app for future reference.

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

Resistor Plus has an age rating of 4+, making it suitable for a wide range of users interested in electronics.

### How often is Resistor Plus updated?

The latest version of Resistor Plus is 2.0, and it was last updated on March 7, 2026. This indicates a commitment to ongoing development and improvements.

### What are the color codes for resistor bands in Resistor Plus?

Resistor Plus supports standard color codes for band digits (Black-0 to White-9), multipliers (Black-x1 Ω to Violet-x10 MΩ, Gold-0.1 Ω, Silver-0.01 Ω), and tolerance (Brown-1%, Red-2%, Gold-5%, Silver-10%).

## Version history (last 5 releases)

### 2.5 — 2026-04-25

- Optimized for the latest devices.
- Fixed minor bugs.
- Improved and redesigned the UI.

### 2.0 — 2026-03-07

- Updated for the newest devices.
- Minor bugs fixed.

### 1.9 — 2024-07-12

- Updated for the newest devices.
- Minor UI update.
- Minor bugs fixed.

### 1.8 — 2021-05-24

- Update for Newest Devices
- Bug Fixed

### 1.7 — 2018-04-22

This app has been updated by Apple to display the Apple Watch app icon.

- Minor UI Update

## Apps similar to Resistor Plus

| App | Rating | Price | Category |
| --- | --- | --- | --- |
| [Umferðarmerkin](https://appshunter.io/ios/app/umferarmerkin/id1260215256) | 5.0 (2) | Free | Education |
| [Articulation Test Center Hive](https://appshunter.io/ios/app/articulation-test-center-hive/id1629999616) | 4.8 (116) | Free | Education |
| [MyChaffey](https://appshunter.io/ios/app/mychaffey/id6470768753) | 3.0 (6) | Free | Education |
| [CONVERSE: World Travel](https://appshunter.io/ios/app/converse-world-travel/id6443979524) | 5.0 (1) | Free | Education |
| [Amatrol eLearning](https://appshunter.io/ios/app/amatrol-elearning/id1629718364) | 2.2 (6) | Free | Education |

## More apps by Nitrio

- [Coloring Book - Plus](https://appshunter.io/ios/app/coloring-book-plus/id500418548)
- [Premium Clock Plus](https://appshunter.io/ios/app/premium-clock-plus/id502784721)
- [Gold Luxury Clock](https://appshunter.io/ios/app/gold-luxury-clock/id505043266)
- [Ohm Law Calculator](https://appshunter.io/ios/app/ohm-law-calculator/id505900137)
- [Premium Clock](https://appshunter.io/ios/app/premium-clock/id517487778)

All apps by Nitrio: https://appshunter.io/developer/321121189

---

*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 2026-08-15.*