# Model Scaler vs Ruler

The clearest difference is rating: Ruler at 3.7 against Model Scaler's 2.9. Ruler also leads on review sentiment (63% vs 40%). Model Scaler's advantage is in-app purchases (none vs 1) and ads (none vs shown). On price, update cadence and device support there is nothing between them.

Both are free to download. Ruler sells 1 one-off in-app purchase. Model Scaler asks for nothing beyond the download.

Ruler holds the better App Store score, 3.7 against 2.9. Both are backed by a comparable volume of ratings — 12 and 3 respectively. Written reviews point the same way: 40% of Model Scaler's written reviews are positive against 63% of Ruler's.

Model Scaler ships an update every 6 months, Ruler every 5 months. The most recent releases landed on June 11, 2026 and June 1, 2026 respectively.

## The numbers

| Metric | Model Scaler | Ruler |
| --- | --- | --- |
| Price | Free | Free |
| Rating | [2.9 (12 ratings)](https://appshunter.io/ios/app/model-scaler/id528641484/reviews) | **[3.7 (3 ratings)](https://appshunter.io/ios/app/ruler-scale-ruler/id919130707/reviews)** |
| Number of ratings | **12** | 3 |
| Positive reviews | 40.0% of reviews | **63.0% of reviews** |
| In-app purchases | **No** | Yes |
| Ads | **No** | Yes |
| Update frequency | Every 6 months | **Every 5 months** |
| Monetization | **Free** | Free with in-app purchases |
| Size | 11 MB | 4 MB |
| Requires iOS | **9.0** | 15.0 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Woodland Scenics](https://appshunter.io/developer/528641487) | [mitsunori oishi](https://appshunter.io/developer/905649994) |

## What reviewers say

### Model Scaler

[App page](https://appshunter.io/ios/app/model-scaler/id528641484)

This tool instantly converts measurements between U.S. Customary and Metric units for any modeling scale. It's designed to be fast, easy, and efficient for all types of scale modelers.

**Highlights:** Instant scale conversion, U.S. Customary to Metric, Metric to U.S. Customary, Supports any modeling scale, Fast and efficient

**Features:** macOS Compatibility

**In-app purchases:** none


### Ruler

[App page](https://appshunter.io/ios/app/ruler-scale-ruler/id919130707)

This app displays various measurement scales for length, including meters and inches. It allows users to set magnification ratios and reduced scales for different applications. Users can calibrate the ruler and adjust PPI settings for accurate measurements.

**Highlights:** Display various measurement scales, Set magnification ratios, Set reduced scales, Measure in meters and inches, Free mode for custom scales, Calibration for accuracy, PPI setting

**Features:** macOS Compatibility, Family Sharing

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Hide Ads | $0.99 | one-time |


## Frequently asked questions

### Is Model Scaler free?

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

### Is Ruler free?

Ruler is free to download, with in-app purchases available.

### Which has better reviews, Model Scaler or Ruler?

Ruler is rated higher. Model Scaler averages 2.9 out of 5 from 12 ratings, while Ruler averages 3.7 from 3 ratings.

### Do Model Scaler or Ruler have ads?

Ruler shows ads; Model Scaler does not.

### Which is updated more often, Model Scaler or Ruler?

Model Scaler ships an update every 6 months, and Ruler every 5 months. Most recently, Model Scaler was updated on June 11, 2026 and 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.*