# Roll Calculator vs Light Meter LM

Roll Calculator and Light Meter LM both sit at 4.4 stars, but that hides the real split: 40% of Light Meter LM's written reviews are positive against 0% of Roll Calculator's. Light Meter LM also leads on ratings volume (2.6K vs 14). Roll Calculator's advantage is in-app purchases (none vs 3) and iOS requirement (12.0 vs 15.0). On price, rating, update cadence and ads there is nothing between them.

Both are free to download. Light Meter LM sells 3 in-app purchases, starting at $3.49 per month. Roll Calculator asks for nothing beyond the download.

On the App Store both sit at effectively the same score — 4.4 for Roll Calculator against 4.5 for Light Meter LM. That said, the two scores are not equally well evidenced: Light Meter LM has 2.6K ratings behind it against 14, so its average is the more settled of the two. Written reviews are what separate them: 0% of Roll Calculator's written reviews are positive against 40% of Light Meter LM's.

Roll Calculator ships an update fortnightly, Light Meter LM monthly. The most recent releases landed on October 24, 2026 and October 29, 2026 respectively.

## The numbers

| Metric | Roll Calculator | Light Meter LM |
| --- | --- | --- |
| Price | Free | Free |
| Rating | [4.4 (14 ratings)](https://appshunter.io/ios/app/roll-calculator/id1329803577/reviews) | **[4.5 (2.6K ratings)](https://appshunter.io/ios/app/light-meter-lm-3000/id1554264761/reviews)** |
| Number of ratings | 14 | **2.6K** |
| Positive reviews | 0.0% of reviews | **40.4% of reviews** |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | **Fortnightly** | Monthly |
| Monetization | **Free** | Free with in-app purchases |
| Size | 9 MB | 22 MB |
| Requires iOS | **12.0** | 15.0 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Beta Flash Solutions Inc.](https://appshunter.io/developer/1329803576) | [Lightray Innovation GmbH](https://appshunter.io/developer/1031383431) |

## What reviewers say

### Roll Calculator

[App page](https://appshunter.io/ios/app/roll-calculator/id1329803577)

This app helps users calculate full and partial roll dimensions for various materials. It allows for inventory management, saving calculations, and defining custom material templates. Easily switch between Imperial and Metric units for precise measurements.

**Highlights:** Calculate full and partial roll dimensions, Manage inventory with 'My List', Define custom material templates, Switch between Imperial and Metric units, Calculate material area coverage, Determine material length by counting wraps

**Features:** macOS Compatibility

**In-app purchases:** none


### Light Meter LM

[App page](https://appshunter.io/ios/app/light-meter-lm-3000/id1554264761)

Transform your smartphone into a professional light meter. Measure illuminance and color temperature with scientifically validated accuracy, trusted by professionals. Requires a simple diffuser for precise readings.

**Highlights:** Measure illuminance (lux/foot-candle), Measure color temperature (Kelvin), Industry-leading accuracy, Pre-calibrated for your device, Low light sensitivity, Save peak reading, Custom calibration option

**In-app purchases (3)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Continuous Charging | $3.49 | per month |
| Single Charge | $0.99 | one-time |
| Unlimited Battery | $19.99 | one-time |

**What reviewers like**

- 👍 Great app
- 👍 Accurate measurements
- 👍 Easy to use
- 👍 Helpful customer service
- 👍 Useful for science/research

**What reviewers complain about**

- 🐛 Requires diffuser for accurate readings
- 💰 Expensive for a light meter app
- 🔋 Battery/trial period issues
- 🔍 Inconsistent/inaccurate readings
- 🙄 Misleading/deceptive marketing

**Reported bugs**

- Diffuser not recognized even when used
- App locks up/crashes
- Constant diffuser pop-up interruptions

**Requested features**

- Ability to use rear camera
- More flexible diffuser options
- Improved accuracy without diffuser


## Frequently asked questions

### Is Roll Calculator free?

Roll Calculator is free to download, with no in-app purchases.

### Is Light Meter LM free?

Light Meter LM is free to download, with in-app purchases available.

### Which has better reviews, Roll Calculator or Light Meter LM?

Light Meter LM is rated higher. Roll Calculator averages 4.4 out of 5 from 14 ratings, while Light Meter LM averages 4.5 from 2.6K ratings.

### Do Roll Calculator or Light Meter LM have ads?

Neither Roll Calculator nor Light Meter LM shows ads.

### Which is updated more often, Roll Calculator or Light Meter LM?

Roll Calculator ships an update fortnightly, and Light Meter LM monthly. Most recently, Roll Calculator was updated on October 24, 2026 and Light Meter LM on October 29, 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.*