# Carpentry Formulator vs Rainfall Calculator

The clearest difference is price: Carpentry Formulator at Free against Rainfall Calculator's $2.99. Carpentry Formulator also leads on update cadence (every 2 months vs every 29 months) and ratings volume (4 vs 1). Rainfall Calculator's advantage is rating (5.0 vs 3.8) and in-app purchases (none vs 1). On ads and device support there is nothing between them.

Carpentry Formulator is free to download; Rainfall Calculator costs $2.99 up front. Carpentry Formulator sells 1 one-off in-app purchase. Rainfall Calculator asks for nothing beyond the download.

Rainfall Calculator holds the better App Store score, 5.0 against 3.8. Both are backed by a comparable volume of ratings — 4 and 1 respectively.

Carpentry Formulator ships an update every 2 months, Rainfall Calculator every 29 months. The most recent releases landed on September 26, 2026 and September 9, 2026 respectively.

## The numbers

| Metric | Carpentry Formulator | Rainfall Calculator |
| --- | --- | --- |
| Price | **Free** | $2.99 |
| Rating | [3.8 (4 ratings)](https://appshunter.io/ios/app/carpentry-formulator/id305583131/reviews) | **[5.0 (1 ratings)](https://appshunter.io/ios/app/rainfall-calculator/id1446150880/reviews)** |
| Number of ratings | **4** | 1 |
| Positive reviews | 25.0% of reviews | — |
| In-app purchases | Yes | **No** |
| Ads | No | No |
| Update frequency | **Every 2 months** | Every 29 months |
| Monetization | **Free** | Paid |
| Best chart rank | — | **#176** |
| Size | 23 MB | 1 MB |
| Requires iOS | 18.6 | **13** |
| Devices | iPhone, iPad | **iPhone, iPad, iPod** |
| Age rating | 4+ | 4+ |
| Developer | [Historycentral.com](https://appshunter.io/developer/1744330560) | [Nitrio](https://appshunter.io/developer/321121189) |

## What reviewers say

### Carpentry Formulator

[App page](https://appshunter.io/ios/app/carpentry-formulator/id305583131)

This app provides over 150 formulas and dozens of conversions for carpenters and builders. It calculates loads on walls and headers, material quantities for projects, and dimensions for roofing and stairs. It also includes area and volume calculations for various shapes.

**Highlights:** Load calculations for walls and headers, Material quantity estimation (joists, studs, concrete), Roofing and stair dimension calculations, Area and volume formulas for geometric shapes, Dozens of unit conversion tools, Shareable calculation results

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

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Professional Features | $2.99 | one-time |


### Rainfall Calculator

[App page](https://appshunter.io/ios/app/rainfall-calculator/id1446150880)

**Currently charting:** #176 Top Paid · Productivity (US App Store)

Calculate potential rainwater harvest volume and cost savings. This tool helps determine annual water collection capacity based on rainfall and roof area, recommending optimal tank sizes for efficient water storage. It also allows for cost-saving analysis by comparing harvested water to mains water prices.

**Highlights:** Instant rainwater calculation, Cost savings evaluation, Minimum tank size recommendation, Supports various input units, Formula references included, Results copyable to other apps

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is Carpentry Formulator free?

Carpentry Formulator is free to download, with in-app purchases available.

### Is Rainfall Calculator free?

Rainfall Calculator costs $2.99, with no in-app purchases.

### Which has better reviews, Carpentry Formulator or Rainfall Calculator?

Rainfall Calculator is rated higher. Carpentry Formulator averages 3.8 out of 5 from 4 ratings, while Rainfall Calculator averages 5.0 from 1 ratings.

### Do Carpentry Formulator or Rainfall Calculator have ads?

Neither Carpentry Formulator nor Rainfall Calculator shows ads.

### Which is updated more often, Carpentry Formulator or Rainfall Calculator?

Carpentry Formulator ships an update every 2 months, and Rainfall Calculator every 29 months. Most recently, Carpentry Formulator was updated on September 26, 2026 and Rainfall Calculator on September 9, 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.*