# Stoichiometry vs DrPhos' Chemistry Pro

The clearest difference is review sentiment: DrPhos' Chemistry Pro at 100% against Stoichiometry's 50%. DrPhos' Chemistry Pro also leads on update cadence (every 9 days vs every 2 months). Stoichiometry's advantage is price ($2.99 vs $4.99). On ads, in-app purchases, monetization model and device support there is nothing between them.

Stoichiometry costs $2.99 and DrPhos' Chemistry Pro $4.99 up front. Neither carries in-app purchases, so what you see is what you pay.

Stoichiometry ships an update every 2 months, DrPhos' Chemistry Pro every 9 days. The most recent releases landed on November 2, 2026 and November 4, 2026 respectively.

## The numbers

| Metric | Stoichiometry | DrPhos' Chemistry Pro |
| --- | --- | --- |
| Price | **$2.99** | $4.99 |
| Rating | — | **[5.0 (6 ratings)](https://appshunter.io/ios/app/drphos-chemistry-pro/id6477353606/reviews)** |
| Number of ratings | — | **6** |
| Positive reviews | 50.0% of reviews | **100.0% of reviews** |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 2 months | **Every 9 days** |
| Monetization | Paid | Paid |
| Size | 1 MB | 19 MB |
| Requires iOS | **17.1** | 17.2 |
| Devices | iPhone, iPad | iPhone, iPad |
| Age rating | 4+ | 4+ |
| Developer | [Roman Volinsky](https://appshunter.io/developer/977951850) | [Monte L Helm](https://appshunter.io/developer/1715082616) |

## What reviewers say

### Stoichiometry

[App page](https://appshunter.io/ios/app/stoichiometry/id1330949637)

This tool helps balance chemical reactions and calculate molar masses, moles, and actual masses of reactants and products. It supports various formula formats and can identify limiting reagents. Data can be sent to another app for gas phase calculations.

**Highlights:** Balance chemical reactions, Calculate molar masses, Determine moles and actual masses, Identify limiting reagents, Supports various formula formats, Integrates with Gas Phase Stoichiometry app

**Features:** Vision Pro support

**In-app purchases:** none


### DrPhos' Chemistry Pro

[App page](https://appshunter.io/ios/app/drphos-chemistry-pro/id6477353606)

This comprehensive chemistry toolkit simplifies complex calculations and problem-solving for students. It offers tools for stoichiometry, pH, molar mass, and balancing chemical equations, making it ideal for high school and college-level chemistry.

**Highlights:** Science Calculator with sig fig control, Molar Mass Calculator, Equation Balancer, Stoichiometry Solver, pH Calculator, Offline Support

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

**In-app purchases:** none


## Frequently asked questions

### Is Stoichiometry free?

Stoichiometry costs $2.99, with no in-app purchases.

### Is DrPhos' Chemistry Pro free?

DrPhos' Chemistry Pro costs $4.99, with no in-app purchases.

### Do Stoichiometry or DrPhos' Chemistry Pro have ads?

Neither Stoichiometry nor DrPhos' Chemistry Pro shows ads.

### Which is updated more often, Stoichiometry or DrPhos' Chemistry Pro?

Stoichiometry ships an update every 2 months, and DrPhos' Chemistry Pro every 9 days. Most recently, Stoichiometry was updated on November 2, 2026 and DrPhos' Chemistry Pro on November 4, 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.*