# 555 Calc vs Resistor Code Calculators

The clearest difference is update cadence: Resistor Code Calculators at every 7 months against 555 Calc's every 20 months. 555 Calc's advantage is iOS requirement (11.0 vs 13.4). On price, ads, in-app purchases and device support there is nothing between them.

Both are free to download. Neither carries in-app purchases, so what you see is what you pay.

555 Calc ships an update every 20 months, Resistor Code Calculators every 7 months. The most recent releases landed on September 27, 2026 and September 17, 2026 respectively.

## The numbers

| Metric | 555 Calc | Resistor Code Calculators |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[4.0 (3 ratings)](https://appshunter.io/ios/app/555-calc/id868058244/reviews)** | — |
| Number of ratings | **3** | — |
| Positive reviews | 50.0% of reviews | — |
| In-app purchases | No | No |
| Ads | Yes | Yes |
| Update frequency | Every 20 months | **Every 7 months** |
| Monetization | Ad-supported | — |
| Size | 18 MB | 6 MB |
| Requires iOS | **11.0** | 13.4 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Jibiki Works](https://appshunter.io/developer/556845808) | [Kanta Kikubo](https://appshunter.io/developer/1450598215) |

## What reviewers say

### 555 Calc

[App page](https://appshunter.io/ios/app/555-calc/id868058244)

This utility app helps engineers and hobbyists calculate resistor values for circuits using the Timer IC 555. Simply input frequency, duty ratio, and capacitor values to get the required resistor outputs.

**Highlights:** Calculate resistor values, Input frequency, Input duty ratio, Input capacitor value, Timer IC 555 circuit design

**Features:** macOS Compatibility

**In-app purchases:** none


### Resistor Code Calculators

[App page](https://appshunter.io/ios/app/resistor-code-calculators/id1465336419)

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is 555 Calc free?

555 Calc is free to download, with no in-app purchases.

### Is Resistor Code Calculators free?

Resistor Code Calculators is free to download, with no in-app purchases.

### Do 555 Calc or Resistor Code Calculators have ads?

Both 555 Calc and Resistor Code Calculators show ads.

### Which is updated more often, 555 Calc or Resistor Code Calculators?

555 Calc ships an update every 20 months, and Resistor Code Calculators every 7 months. Most recently, 555 Calc was updated on September 27, 2026 and Resistor Code Calculators on September 17, 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.*