# Millimeter Pro vs 定規(Ruler)

The clearest difference is price: 定規(Ruler) at Free against Millimeter Pro's $3.99. 定規(Ruler) also leads on rating (5.0 vs 4.4) and review sentiment (80% vs 58%). Millimeter Pro's advantage is ratings volume (108 vs 2) and chart position (#188 vs unranked). On update cadence, ads, in-app purchases and monetization model there is nothing between them.

定規(Ruler) is free to download; Millimeter Pro costs $3.99 up front. Neither carries in-app purchases, so what you see is what you pay.

定規(Ruler) holds the better App Store score, 5.0 against 4.4. That said, the two scores are not equally well evidenced: Millimeter Pro has 108 ratings behind it against 2, so its average is the more settled of the two. Written reviews point the same way: 58% of Millimeter Pro's written reviews are positive against 80% of 定規(Ruler)'s.

Millimeter Pro ships an update every 4 months, 定規(Ruler) every 6 months. The most recent releases landed on September 18, 2026 and June 1, 2026 respectively.

## The numbers

| Metric | Millimeter Pro | 定規(Ruler) |
| --- | --- | --- |
| Price | $3.99 | **Free** |
| Rating | [4.4 (108 ratings)](https://appshunter.io/ios/app/millimeter-pro-screen-ruler/id631810777/reviews) | **[5.0 (2 ratings)](https://appshunter.io/ios/app/ruler/id1166028258/reviews)** |
| Number of ratings | **108** | 2 |
| Positive reviews | 57.9% of reviews | **80.0% of reviews** |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | **Every 4 months** | Every 6 months |
| Monetization | Free | Free |
| Best chart rank | **#188** | — |
| Size | 24 MB | 3 MB |
| Requires iOS | **15.0** | 15.6 |
| Devices | **iPhone, iPad, iPod** | iPhone, iPod |
| Age rating | 4+ | 4+ |
| Developer | [VisTech.Projects LLC](https://appshunter.io/developer/620969851) | [Mayumi Kato](https://appshunter.io/developer/705832872) |

## What reviewers say

### Millimeter Pro

[App page](https://appshunter.io/ios/app/millimeter-pro-screen-ruler/id631810777)

**Currently charting:** #188 Top Paid · Utilities (US App Store)

This app transforms your device into a versatile measuring tool. It allows for precise measurements of length, area, diameter, and angles using the touchscreen. Easily split objects into equal parts and switch between millimeters and inches for your convenience.

**Highlights:** Touchscreen ruler and tape measure, Measure length, area, diameter, and angles, Split objects into equal parts, Supports millimeters and inches, Estimate radius, Thread pitch gauge

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

**In-app purchases:** none


### 定規(Ruler)

[App page](https://appshunter.io/ios/app/ruler/id1166028258)

A straightforward measuring tool for iPhones, offering accurate measurements in both millimeters and inches. It's designed for ease of use and provides a cool, functional experience for everyday measuring needs.

**Highlights:** Accurate measurements, Millimeter display, Inch display, Supports all iPhone sizes, Simple interface

**In-app purchases:** none


## Frequently asked questions

### Is Millimeter Pro free?

Millimeter Pro costs $3.99, with no in-app purchases.

### Is 定規(Ruler) free?

定規(Ruler) is free to download, with no in-app purchases.

### Which has better reviews, Millimeter Pro or 定規(Ruler)?

定規(Ruler) is rated higher. Millimeter Pro averages 4.4 out of 5 from 108 ratings, while 定規(Ruler) averages 5.0 from 2 ratings.

### Do Millimeter Pro or 定規(Ruler) have ads?

Neither Millimeter Pro nor 定規(Ruler) shows ads.

### Which is updated more often, Millimeter Pro or 定規(Ruler)?

Millimeter Pro ships an update every 4 months, and 定規(Ruler) every 6 months. Most recently, Millimeter Pro was updated on September 18, 2026 and 定規(Ruler) on June 1, 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.*