# Phase Calc vs Confidence Interval Calc

The clearest difference is price: Confidence Interval Calc at Free against Phase Calc's $1.99. Confidence Interval Calc also leads on update cadence (every 6 days vs every 6 weeks) and iOS requirement (13.0 vs 17.0). On ads, in-app purchases and device support there is nothing between them.

Confidence Interval Calc is free to download; Phase Calc costs $1.99 up front. Neither carries in-app purchases, so what you see is what you pay.

Phase Calc ships an update every 6 weeks, Confidence Interval Calc every 6 days. The most recent releases landed on August 1, 2026 and September 9, 2026 respectively.

## The numbers

| Metric | Phase Calc | Confidence Interval Calc |
| --- | --- | --- |
| Price | $1.99 | **Free** |
| Rating | **[5.0 (4 ratings)](https://appshunter.io/ios/app/phase-calc/id837266300/reviews)** | — |
| Number of ratings | **4** | — |
| Positive reviews | 100.0% of reviews | — |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 6 weeks | **Every 6 days** |
| Monetization | Paid | — |
| Size | 13 MB | 30 MB |
| Requires iOS | 17.0 | **13.0** |
| Devices | iPhone, iPad | **iPhone, iPad, iPod** |
| Age rating | 4+ | 17+ |
| Developer | [Donnie Herman](https://appshunter.io/developer/837266303) | [Arsosa Network Inc.](https://appshunter.io/developer/1209042440) |

## What reviewers say

### Phase Calc

[App page](https://appshunter.io/ios/app/phase-calc/id837266300)

This advanced engineering app performs complex electrical calculations for three-phase power systems. It offers tools for students, technicians, and engineers to analyze unbalanced systems, perform sequence transformations, and access reference libraries. Results can be easily exported for documentation and sharing.

**Highlights:** Symmetrical component analysis, Three-phase power system calculations, Phase-to-sequence and sequence-to-phase transformations, Polar and rectangular input support, Specialized calculators and reference libraries, Exportable results for documentation

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

**In-app purchases:** none


### Confidence Interval Calc

[App page](https://appshunter.io/ios/app/confidence-interval-calc/id6749201174)

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is Phase Calc free?

Phase Calc costs $1.99, with no in-app purchases.

### Is Confidence Interval Calc free?

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

### Do Phase Calc or Confidence Interval Calc have ads?

Neither Phase Calc nor Confidence Interval Calc shows ads.

### Which is updated more often, Phase Calc or Confidence Interval Calc?

Phase Calc ships an update every 6 weeks, and Confidence Interval Calc every 6 days. Most recently, Phase Calc was updated on August 1, 2026 and Confidence Interval Calc on September 9, 2026.

---

*Compared by [AppsHunter](https://appshunter.io/) from daily US App Store data. Review summaries are generated from verbatim App Store reviews.*