# TDCA vs Stair Calculator

The clearest difference is rating: Stair Calculator at 4.1 against TDCA's 2.0. Stair Calculator also leads on ratings volume (738 vs 1) and review sentiment (21% vs 0%). TDCA's advantage is in-app purchases (none vs 2) and iOS requirement (7.0 vs 15.0). On price, update cadence, ads and device support there is nothing between them.

Both are free to download. Stair Calculator sells 2 in-app purchases, starting at $9.99 per year. TDCA asks for nothing beyond the download.

Stair Calculator holds the better App Store score, 4.1 against 2.0. That said, the two scores are not equally well evidenced: Stair Calculator has 738 ratings behind it against 1, so its average is the more settled of the two. Written reviews point the same way: 0% of TDCA's written reviews are positive against 21% of Stair Calculator's.

TDCA ships an update every 2 months, Stair Calculator every 3 months. The most recent releases landed on September 22, 2026 and September 18, 2026 respectively.

## The numbers

| Metric | TDCA | Stair Calculator |
| --- | --- | --- |
| Price | Free | Free |
| Rating | [2.0 (1 ratings)](https://appshunter.io/ios/app/tdca/id640086167/reviews) | **[4.1 (738 ratings)](https://appshunter.io/ios/app/stair-calculator-construction/id1493037366/reviews)** |
| Number of ratings | 1 | **738** |
| Positive reviews | 0.0% of reviews | **21.4% of reviews** |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | **Every 2 months** | Every 3 months |
| Monetization | **Free** | Free with in-app purchases |
| Size | 7 MB | 1 MB |
| Requires iOS | **7.0** | 15.0 |
| Devices | iPhone, iPod | **iPhone, iPad, iPod** |
| Age rating | 4+ | 4+ |
| Developer | [AVIA](https://appshunter.io/developer/390606207) | [Phan Nhat Đang](https://appshunter.io/developer/1437390098) |

## What reviewers say

### TDCA

[App page](https://appshunter.io/ios/app/tdca/id640086167)

Easily estimate the materials needed for decks, terraces, or docks. Select timber types and deck shapes to get a material quantity estimate. Includes inspirational photos and an FAQ section.

**Highlights:** Material quantity estimation, Timber type selection, Deck shape selection, Email material lists, Inspirational construction photos, FAQ section

**Features:** Vision Pro support

**In-app purchases:** none


### Stair Calculator

[App page](https://appshunter.io/ios/app/stair-calculator-construction/id1493037366)

This app calculates essential parameters for stair construction, offering flexibility in input and providing multiple step set options. It supports various units and allows results to be easily copied.

**Highlights:** Calculate stair construction parameters, Flexible input for Run or Total Run, Determine largest and smallest step sets, Support for various units, Copy results to clipboard

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

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Annual Premium Package | $9.99 | per year |
| Unlock all features | $5.99 | one-time |

**What reviewers like**

- 👍 Easy to use
- 🚀 Helpful information
- 🚀 Provides useful calculations

**What reviewers complain about**

- 🐛 Doesn't work as expected
- 🔒 No way to cancel subscription
- 🔒 Difficult to cancel trial
- 🤬 Obnoxious ads
- 🤬 Misleading as a learning tool

**Reported bugs**

- Subscription numbers don't add up
- Doesn't provide promised features after purchase

**Requested features**

- Option to uninstall app
- Ability to calculate run based on rise and landing space
- Provide more detailed diagrams and visuals


## Frequently asked questions

### Is TDCA free?

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

### Is Stair Calculator free?

Stair Calculator is free to download, with in-app purchases available.

### Which has better reviews, TDCA or Stair Calculator?

Stair Calculator is rated higher. TDCA averages 2.0 out of 5 from 1 ratings, while Stair Calculator averages 4.1 from 738 ratings.

### Do TDCA or Stair Calculator have ads?

Neither TDCA nor Stair Calculator shows ads.

### Which is updated more often, TDCA or Stair Calculator?

TDCA ships an update every 2 months, and Stair Calculator every 3 months. Most recently, TDCA was updated on September 22, 2026 and Stair Calculator on September 18, 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.*