# Molarity Abacus vs Ring Sizer

The clearest difference is update cadence: Ring Sizer at every 3 weeks against Molarity Abacus's every 12 months. Ring Sizer also leads on rating (4.8 vs 4.5). Molarity Abacus's advantage is review sentiment (100% vs 71%) and iOS requirement (8.0 vs 17.0). On price, ratings volume, ads and in-app purchases there is nothing between them.

Both are free to download. Molarity Abacus sells 1 one-off in-app purchase and Ring Sizer sells 3 in-app purchases, starting at $3.99 per 7 days. Whichever you choose, the download price is not the number that matters.

Ring Sizer holds the better App Store score, 4.8 against 4.5. Both are backed by a comparable volume of ratings — 15 and 35 respectively. Written reviews complicate that: 100% of Molarity Abacus's written reviews are positive against 71% of Ring Sizer's, so the app with the better star average is not the one people write more warmly about.

Molarity Abacus ships an update every 12 months, Ring Sizer every 3 weeks. The most recent releases landed on September 20, 2026 and September 21, 2026 respectively.

## The numbers

| Metric | Molarity Abacus | Ring Sizer |
| --- | --- | --- |
| Price | Free | Free |
| Rating | [4.5 (15 ratings)](https://appshunter.io/ios/app/molarity-abacus/id915807653/reviews) | **[4.8 (35 ratings)](https://appshunter.io/ios/app/ring-sizer-ring-measure/id6739887211/reviews)** |
| Number of ratings | 15 | **35** |
| Positive reviews | **100.0% of reviews** | 71.4% of reviews |
| In-app purchases | Yes | Yes |
| Ads | No | No |
| Update frequency | Every 12 months | **Every 3 weeks** |
| Monetization | Free with in-app purchases | Free with in-app purchases |
| Size | 2 MB | 29 MB |
| Requires iOS | **8.0** | 17.0 |
| Devices | iPhone, iPod | iPhone, iPad |
| Age rating | 4+ | 4+ |
| Developer | [Oak Driven LLC](https://appshunter.io/developer/915807656) | [Ramkumar Vellaisamy](https://appshunter.io/developer/1706335914) |

## What reviewers say

### Molarity Abacus

[App page](https://appshunter.io/ios/app/molarity-abacus/id915807653)

Easily calculate molarity, solution volume, solute mass, or molecular weight by inputting any three variables. Customize units and access pre-configured strong acids and bases. An in-app purchase allows for creating and storing custom compounds.

**Highlights:** Molarity calculation, Solute mass calculation, Total solution volume calculation, Molecular weight calculation, Customizable units, Pre-configured compounds, Create and store custom compounds

**Features:** macOS Compatibility

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Create and Save Compounds | Free | one-time |


### Ring Sizer

[App page](https://appshunter.io/ios/app/ring-sizer-ring-measure/id6739887211)

Instantly determine your precise ring size for online shopping, custom orders, or gift purchases. Offers multiple international sizing standards and saves your measurements for future use. Get accurate results with clear, step-by-step instructions.

**Highlights:** Instant ring size measurement, Support for multiple international sizing standards, Save and access size history, Step-by-step measurement guidance, Measure for custom ring widths

**In-app purchases (3)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Ring Sizer Weekly | $3.99 | per 7 days |
| Ring Sizer Yearly | $9.99 | per year |
| Ring Sizer Lifetime | $19.99 | one-time |


## Frequently asked questions

### Is Molarity Abacus free?

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

### Is Ring Sizer free?

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

### Which has better reviews, Molarity Abacus or Ring Sizer?

Ring Sizer is rated higher. Molarity Abacus averages 4.5 out of 5 from 15 ratings, while Ring Sizer averages 4.8 from 35 ratings.

### Do Molarity Abacus or Ring Sizer have ads?

Neither Molarity Abacus nor Ring Sizer shows ads.

### Which is updated more often, Molarity Abacus or Ring Sizer?

Molarity Abacus ships an update every 12 months, and Ring Sizer every 3 weeks. Most recently, Molarity Abacus was updated on September 20, 2026 and Ring Sizer on September 21, 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.*