# Stoichiometry vs DrPhos' Stoichiometry

The clearest difference is in-app purchases: Stoichiometry at none against DrPhos' Stoichiometry's 11. DrPhos' Stoichiometry's advantage is update cadence (every 3 weeks vs every 2 months) and price ($0.99 vs $2.99). On ads, monetization model, device support and iOS requirement there is nothing between them.

Stoichiometry costs $2.99 and DrPhos' Stoichiometry $0.99 up front. DrPhos' Stoichiometry sells 11 one-off in-app purchases. Stoichiometry asks for nothing beyond the download.

Stoichiometry ships an update every 2 months, DrPhos' Stoichiometry every 3 weeks. The most recent releases landed on September 7, 2026 and September 20, 2026 respectively.

## The numbers

| Metric | Stoichiometry | DrPhos' Stoichiometry |
| --- | --- | --- |
| Price | $2.99 | **$0.99** |
| Rating | — | **[5.0 (1 ratings)](https://appshunter.io/ios/app/drphos-stoichiometry/id6475633178/reviews)** |
| Number of ratings | — | **1** |
| Positive reviews | 50.0% of reviews | — |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | Every 2 months | **Every 3 weeks** |
| Monetization | Paid | Paid |
| Size | 1 MB | 15 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' Stoichiometry

[App page](https://appshunter.io/ios/app/drphos-stoichiometry/id6475633178)

This tool simplifies solving chemical reaction problems by allowing users to input balanced equations and identify known and unknown compounds. It instantly calculates moles and mass, assisting students with various stoichiometry challenges.

**Highlights:** Mole, mass, and volume conversions, Balanced chemical equation support, Compound selection, Limiting reactant detection, High school and college chemistry focus

**Features:** macOS Compatibility

**In-app purchases (11)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Significant Figures Counter | $0.99 | one-time |
| Science Calculator | $0.99 | one-time |
| Quadratic Equation Solver | $0.99 | one-time |
| Kinetics | $0.99 | one-time |
| Molar Mass Calculator | $0.99 | one-time |
| General Chemistry Naming | $0.99 | one-time |
| Ionic Compound Builder | $0.99 | one-time |
| Solution Concentrations | $0.99 | one-time |
| Reaction Balancer | $0.99 | one-time |
| pH Calculator | $0.99 | one-time |
| Stoichiometry | $0.99 | one-time |


## Frequently asked questions

### Is Stoichiometry free?

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

### Is DrPhos' Stoichiometry free?

DrPhos' Stoichiometry costs $0.99, and also offers in-app purchases.

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

Neither Stoichiometry nor DrPhos' Stoichiometry shows ads.

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

Stoichiometry ships an update every 2 months, and DrPhos' Stoichiometry every 3 weeks. Most recently, Stoichiometry was updated on September 7, 2026 and DrPhos' Stoichiometry on September 20, 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.*