# Span Calc vs Stair Calculator

The clearest difference is rating: Stair Calculator at 4.1 against Span Calc's 3.0. Stair Calculator also leads on ratings volume (740 vs 16). Span Calc's advantage is in-app purchases (none vs 2) and update cadence (every 10 days vs every 3 months). On price, ads, device support and iOS requirement there is nothing between them.

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

Stair Calculator holds the better App Store score, 4.1 against 3.0. That said, the two scores are not equally well evidenced: Stair Calculator has 740 ratings behind it against 16, so its average is the more settled of the two. Written reviews complicate that: 30% of Span Calc's written reviews are positive against 21% of Stair Calculator's, so the app with the better star average is not the one people write more warmly about.

Span Calc ships an update every 10 days, Stair Calculator every 3 months. The most recent releases landed on October 23, 2026 and October 24, 2026 respectively.

## The numbers

| Metric | Span Calc | Stair Calculator |
| --- | --- | --- |
| Price | Free | Free |
| Rating | [3.0 (16 ratings)](https://appshunter.io/ios/app/span-calc/id380481343/reviews) | **[4.1 (740 ratings)](https://appshunter.io/ios/app/stair-calculator-construction/id1493037366/reviews)** |
| Number of ratings | 16 | **740** |
| Positive reviews | **29.6% of reviews** | 21.4% of reviews |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | **Every 10 days** | Every 3 months |
| Monetization | **Free** | Free with in-app purchases |
| Size | 168 MB | 1 MB |
| Requires iOS | **14.2** | 15.0 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 17+ | 4+ |
| Developer | [American Wood Council](https://appshunter.io/developer/380481346) | [Phan Nhat Đang](https://appshunter.io/developer/1437390098) |

## What reviewers say

### Span Calc

[App page](https://appshunter.io/ios/app/span-calc/id380481343)

Calculate maximum horizontal spans for wood joists and rafters using various lumber species and grades. Compares multiple options for common loading conditions based on NDS® standards.

**Highlights:** Calculates joist and rafter spans, Supports all softwood and hardwood lumber, Uses 2021 NDS® for Wood Construction, Compares multiple species and grades, Handles common loading conditions

**Features:** macOS Compatibility

**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 Span Calc free?

Span Calc 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, Span Calc or Stair Calculator?

Stair Calculator is rated higher. Span Calc averages 3.0 out of 5 from 16 ratings, while Stair Calculator averages 4.1 from 740 ratings.

### Do Span Calc or Stair Calculator have ads?

Neither Span Calc nor Stair Calculator shows ads.

### Which is updated more often, Span Calc or Stair Calculator?

Span Calc ships an update every 10 days, and Stair Calculator every 3 months. Most recently, Span Calc was updated on October 23, 2026 and Stair Calculator on October 24, 2026.

---

*Compared by [AppsHunter](https://appshunter.io/) from daily US App Store data. Review summaries are generated from verbatim App Store reviews.*