# SI Prefix Converter vs Vector Calculator Plus

The clearest difference is price: SI Prefix Converter at Free against Vector Calculator Plus's $2.99. SI Prefix Converter also leads on update cadence (every 9 months vs every 43 months) and iOS requirement (8.0 vs 13). On ads, in-app purchases and device support there is nothing between them.

SI Prefix Converter is free to download; Vector Calculator Plus costs $2.99 up front. Neither carries in-app purchases, so what you see is what you pay.

SI Prefix Converter ships an update every 9 months, Vector Calculator Plus every 43 months. The most recent releases landed on October 13, 2026 and October 18, 2026 respectively.

## The numbers

| Metric | SI Prefix Converter | Vector Calculator Plus |
| --- | --- | --- |
| Price | **Free** | $2.99 |
| Rating | — | **[2.5 (2 ratings)](https://appshunter.io/ios/app/vector-calculator-plus/id1630864948/reviews)** |
| Number of ratings | — | **2** |
| Positive reviews | — | 0.0% of reviews |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | **Every 9 months** | Every 43 months |
| Monetization | — | Paid |
| Size | 23 MB | 1 MB |
| Requires iOS | **8.0** | 13 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Yuki Takeda](https://appshunter.io/developer/1021096508) | [Heng Jia Liang](https://appshunter.io/developer/1532000635) |

## What reviewers say

### SI Prefix Converter

[App page](https://appshunter.io/ios/app/si-prefix-converter/id1047118885)

**Features:** Vision Pro support

**In-app purchases:** none


### Vector Calculator Plus

[App page](https://appshunter.io/ios/app/vector-calculator-plus/id1630864948)

This app simplifies vector addition for students and educators. It allows for quick calculations of multiple vectors, visualizing the results with generated graphs. Users can customize graph elements and save images for later use.

**Highlights:** Instant vector calculation, Add multiple vectors by x, y, magnitude, or angle, Generate vector images, Save vector images to camera roll, Customize graph display options, Set background color for graphs

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

**In-app purchases:** none


## Frequently asked questions

### Is SI Prefix Converter free?

SI Prefix Converter is free to download, with no in-app purchases.

### Is Vector Calculator Plus free?

Vector Calculator Plus costs $2.99, with no in-app purchases.

### Do SI Prefix Converter or Vector Calculator Plus have ads?

Neither SI Prefix Converter nor Vector Calculator Plus shows ads.

### Which is updated more often, SI Prefix Converter or Vector Calculator Plus?

SI Prefix Converter ships an update every 9 months, and Vector Calculator Plus every 43 months. Most recently, SI Prefix Converter was updated on October 13, 2026 and Vector Calculator Plus on October 18, 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.*