# Thermodynamics Calculator vs Dirr

The clearest difference is price: Dirr at Free against Thermodynamics Calculator's $1.99. Dirr also leads on update cadence (every 3 days vs every 7 months) and iOS requirement (12.0 vs 16.1). On ads, in-app purchases and device support there is nothing between them.

Dirr is free to download; Thermodynamics Calculator costs $1.99 up front. Neither carries in-app purchases, so what you see is what you pay.

Thermodynamics Calculator ships an update every 7 months, Dirr every 3 days. The most recent releases landed on October 23, 2026 and October 15, 2026 respectively.

## The numbers

| Metric | Thermodynamics Calculator | Dirr |
| --- | --- | --- |
| Price | $1.99 | **Free** |
| Rating | **[4.0 (30 ratings)](https://appshunter.io/ios/app/thermodynamics-calculator/id521684348/reviews)** | — |
| Number of ratings | **30** | — |
| Positive reviews | 50.0% of reviews | — |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 7 months | **Every 3 days** |
| Monetization | Paid | — |
| Size | 11 MB | 54 MB |
| Requires iOS | 16.1 | **12.0** |
| Devices | iPhone, iPad | **iPhone, iPad, iPod** |
| Age rating | +4 | 4+ |
| Developer | [V PUGAZHENTHI](https://appshunter.io/developer/491898049) | [Orth Ltd](https://appshunter.io/developer/1510153418) |

## What reviewers say

### Thermodynamics Calculator

[App page](https://appshunter.io/ios/app/thermodynamics-calculator/id521684348)

This app offers 44 essential thermodynamics calculators and thermal engineering tables. It provides quick access to formulas, definitions, and data, making it a valuable tool for engineers and students.

**Highlights:** 44 thermodynamics calculators, Thermal engineering tables, Formulas, tables, and definitions, Compatible with iPhone and iPad, Quick and easy reference

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

**In-app purchases:** none


### Dirr

[App page](https://appshunter.io/ios/app/dirr/id6444596100)

**In-app purchases:** none


## Frequently asked questions

### Is Thermodynamics Calculator free?

Thermodynamics Calculator costs $1.99, with no in-app purchases.

### Is Dirr free?

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

### Do Thermodynamics Calculator or Dirr have ads?

Neither Thermodynamics Calculator nor Dirr shows ads.

### Which is updated more often, Thermodynamics Calculator or Dirr?

Thermodynamics Calculator ships an update every 7 months, and Dirr every 3 days. Most recently, Thermodynamics Calculator was updated on October 23, 2026 and Dirr on October 15, 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.*