Phase Calc vs SI Prefix Converter
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
Phase Calc
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.
- 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
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Phase Calc for iOS is an advanced engineering app for most electrical designs, expecially symmetrical component analysis and three-phase power system calculations. Built for students, teachers, technicians, and engineers, it combines a polished mobile experience with a powerful technical workflow for fast, accurate analysis of unbalanced three-phase systems in the field, lab, or classroom. The app performs both phase-to-sequence and sequence-to-phase transformations, with support for inputs in polar and rectangular form. It quickly resolves three unbalanced phase quantities into their positive-, negative-, and zero-sequence components, making it a practical tool for protection studies, fault analysis, system modeling, relay validation, and coursework. More than a single-purpose calculator, Phase Calc is packed with specialized calculators, technical reference libraries, and built-in formulas to support everyday power systems work. Whether you are checking values, reviewing theory, or working through engineering problems more efficiently, the app puts essential tools in one place. Results can be exported instantly, including vector data for plotting and graphical analysis, as well as technical report exports for documentation, review, and sharing. With powerful capabilities in a streamlined interface, Phase Calc delivers a complete mobile toolkit for three-phase analysis on iPhone and iPad.
SI Prefix Converter
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This is a change tool of SI Prefix. It's possible to change all SI prefixes mutually.
Screenshots
Verdict
The clearest difference is price: SI Prefix Converter at Free against Phase Calc's $1.99. SI Prefix Converter also leads on iOS requirement (8.0 vs 17.0). Phase Calc's advantage is update cadence (every 6 weeks vs every 9 months). On ads, in-app purchases and device support there is nothing between them.
Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS
SI Prefix Converter 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, SI Prefix Converter every 9 months. The most recent releases landed on October 23, 2026 and October 13, 2026 respectively.
| Parameter | Phase Calc | SI Prefix Converter |
|---|---|---|
| Price | $1.99 | Free — better |
| Rating | 5.0 (4 ratings) — better | — |
| Positive reviews | 100.0% of reviews | — |
| Number of ratings | 4 — better | — |
| Update frequency | Every 6 weeks — better | Every 9 months |
| Ads | No | No |
| In-app purchases | No | No |
| Monetization | Paid | — |
| Devices | iPhone, iPad | iPhone, iPad, iPod — better |
| Requires iOS | 17.0 | 8.0 — better |
| Further details — not scored | ||
| Size | 13 MB | 23 MB |
| Age rating | 4+ | 4+ |
| Developer | Donnie Herman | Yuki Takeda |
In-app purchases
Phase Calc
No in-app purchases
SI Prefix Converter
No in-app purchases
Questions
Is Phase Calc free?
Is SI Prefix Converter free?
Do Phase Calc or SI Prefix Converter have ads?
Which is updated more often, Phase Calc or SI Prefix Converter?
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