# Resistor calc vs SistroFix

The clearest difference is price: SistroFix at Free against Resistor calc's $1.99. SistroFix also leads on update cadence (daily vs every 2 months). Resistor calc's advantage is iOS requirement (13.0 vs 16.4). On ads, in-app purchases and device support there is nothing between them.

SistroFix is free to download; Resistor calc costs $1.99 up front. Neither carries in-app purchases, so what you see is what you pay.

Resistor calc ships an update every 2 months, SistroFix daily. The most recent releases landed on October 2, 2026 and September 30, 2026 respectively.

## The numbers

| Metric | Resistor calc | SistroFix |
| --- | --- | --- |
| Price | $1.99 | **Free** |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 2 months | **Daily** |
| Size | 17 MB | 57 MB |
| Requires iOS | **13.0** | 16.4 |
| Devices | **iPhone, iPad, iPod** | iPhone, iPad |
| Age rating | 4+ | 4+ |
| Developer | [Anas Abubakar](https://appshunter.io/developer/1581534101) | [Kevin Manuel Lorenzo Huise](https://appshunter.io/developer/1893257478) |

## What reviewers say

### Resistor calc

[App page](https://appshunter.io/ios/app/resistor-calc-electronics/id6477826973)

**Features:** macOS Compatibility, Vision Pro support

**In-app purchases:** none


### SistroFix

[App page](https://appshunter.io/ios/app/sistrofix/id6762180498)

**Features:** macOS Compatibility, Vision Pro support

**In-app purchases:** none


## Frequently asked questions

### Is Resistor calc free?

Resistor calc costs $1.99, with no in-app purchases.

### Is SistroFix free?

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

### Do Resistor calc or SistroFix have ads?

Neither Resistor calc nor SistroFix shows ads.

### Which is updated more often, Resistor calc or SistroFix?

Resistor calc ships an update every 2 months, and SistroFix daily. Most recently, Resistor calc was updated on October 2, 2026 and SistroFix on September 30, 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.*