# Resistor Calc Toolbox — LED & Resistor Calculators

> LED & Resistor Calculators (iPhone/iPad app by Kevin Kuromi.)

- Source: https://appshunter.io/ios/app/resistor-calc-toolbox/id6817532964 (this page in markdown: same URL + `.md`)
- Developer: [Kevin Kuromi](https://appshunter.io/developer/6816263117)
- Category: Utilities, Education
- Price: $2.99
- Age rating: 4+
- Requires: iOS 17.6 · 5 MB
- Languages: American English
- Released: 2026-10-13
- Data updated: 2026-10-15

## What is Resistor Calc Toolbox?

Resistor Calc Toolbox is a simple, easy-to-use electronics utility for working with LEDs and 4-band resistors.
Three calculators put commonly needed resistor information in one convenient app.
LED Resistor Calculator
Enter the supply voltage, LED forward voltage, and LED current to calculate the required resistance and minimum resistor power rating.
Color Bands → Ohms
Select the four resistor color bands to calculate the resistance value, tolerance, and tolerance range.
Ohms → Color Bands
Enter a resistance value and tolerance to find the corresponding 4-band resistor colors.
Features
• Three resistor tools in one app
• LED resistance and power calculations
• 4-band resistor color code decoding
• Resistance-to-color-band conversion
• Resistance tolerance range
• Support for common resistor multiplier and tolerance colors
• Clean, straightforward interface
• Works on iPhone and iPad
Whether you're working at the electronics bench, experimenting with LED circuits, or simply need a quick resistor reference, Resistor Calc Toolbox keeps the calculations close at hand.
Important: Calculations are based on the values you enter and are provided as a design aid. Verify component values, ratings, tolerances, and suitability for your specific circuit before use.

I particularly like including our disclaimer at the bottom of the App Store description. It doesn't interfere with the sales pitch, but it's visible before purchase.

## Is Resistor Calc Toolbox safe?

Not enough ratings yet to assess Resistor Calc Toolbox.

## Is Resistor Calc Toolbox legit?

Resistor Calc Toolbox has limited verification signals. The AppsHunter Legitimacy Score for Resistor Calc Toolbox is 58 out of 100 points across 7 verification signals from App Store and developer data.


## Version history (last 1 release)

### 1.0 — 2026-10-14

No release notes.

## More apps by Kevin Kuromi

- [Graphic Layout Calculator](https://appshunter.io/ios/app/graphic-layout-calculator/id6816263115)

All apps by Kevin Kuromi: https://appshunter.io/developer/6816263117

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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 2026-10-15.*