# Ohms Law Calc. vs Selsystem

The clearest difference is in-app purchases: Selsystem at none against Ohms Law Calc.'s 1. Selsystem also leads on ads (none vs shown) and update cadence (every 8 days vs every 2 months). On price, device support and iOS requirement there is nothing between them.

Both are free to download. Ohms Law Calc. sells 1 one-off in-app purchase. Selsystem asks for nothing beyond the download.

Ohms Law Calc. ships an update every 2 months, Selsystem every 8 days. The most recent releases landed on October 23, 2026 and October 10, 2026 respectively.

## The numbers

| Metric | Ohms Law Calc. | Selsystem |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[4.7 (1.3K ratings)](https://appshunter.io/ios/app/ohms-law-calc/id491898006/reviews)** | — |
| Number of ratings | **1.3K** | — |
| Positive reviews | 50.0% of reviews | — |
| In-app purchases | Yes | **No** |
| Ads | Yes | **No** |
| Update frequency | Every 2 months | **Every 8 days** |
| Monetization | Free with in-app purchases | — |
| Size | 59 MB | 99 MB |
| Requires iOS | 17.6 | **16.0** |
| Devices | iPhone, iPad | iPhone, iPad |
| Age rating | 4+ | 4+ |
| Developer | [V PUGAZHENTHI](https://appshunter.io/developer/491898049) | [PURPLESOFT SRL](https://appshunter.io/developer/1473279616) |

## What reviewers say

### Ohms Law Calc.

[App page](https://appshunter.io/ios/app/ohms-law-calc/id491898006)

This app provides a comprehensive suite of electrical calculations, including Ohm's Law, voltage drop, wire sizing, and impedance. It also offers numerous converters for various electrical units and parameters, aiding in circuit design and analysis.

**Highlights:** Ohm's Law calculations, Voltage drop calculator, Wire size calculator, Impedance calculations (R, L, C), Electrical unit converters, Power and current conversions, Circuit design tools

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

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Ohms Law Calc. | $3.99 | one-time |

**What reviewers like**

- 🚀 Great value
- 🚀 Works perfectly
- 🚀 Fantastic app
- 👍 Best thing since sliced bread
- 🚀 Useful for electrical work

**What reviewers complain about**

- 👎 Have to pay again for an app already purchased
- 👎 Not easy to use
- 🐛 Paid but not unlocked, no response from developer
- 👎 Annoying pop-ups
- 🐛 Keeps shutting down

**Reported bugs**

- Paid version not unlocking
- Repeatedly prompting for payment after already paid
- Keyboard overlaying results making it difficult to see

**Requested features**

- Add more electrical conversions and calculations
- Add ability to input voltage and resistance to get amps and watts
- Add kVA, rms, and other popular needed conversions


### Selsystem

[App page](https://appshunter.io/ios/app/selsystem/id6747822782)

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

**In-app purchases:** none


## Frequently asked questions

### Is Ohms Law Calc. free?

Ohms Law Calc. is free to download, with in-app purchases available.

### Is Selsystem free?

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

### Do Ohms Law Calc. or Selsystem have ads?

Ohms Law Calc. shows ads; Selsystem does not.

### Which is updated more often, Ohms Law Calc. or Selsystem?

Ohms Law Calc. ships an update every 2 months, and Selsystem every 8 days. Most recently, Ohms Law Calc. was updated on October 23, 2026 and Selsystem on October 10, 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.*