# Plumbing Formulator vs HomeKept

The clearest difference is update cadence: HomeKept at every 3 days against Plumbing Formulator's every 2 months. HomeKept also leads on iOS requirement (15.0 vs 18.6). On price, ads, in-app purchases and device support there is nothing between them.

Both are free to download. Plumbing Formulator sells 4 one-off in-app purchases and HomeKept sells 2 in-app purchases, starting at $4.99 per month. Whichever you choose, the download price is not the number that matters.

Plumbing Formulator ships an update every 2 months, HomeKept every 3 days. The most recent releases landed on October 31, 2026 and November 5, 2026 respectively.

## The numbers

| Metric | Plumbing Formulator | HomeKept |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[4.6 (7 ratings)](https://appshunter.io/ios/app/plumbing-formulator/id303497783/reviews)** | — |
| Number of ratings | **7** | — |
| Positive reviews | 9.1% of reviews | — |
| In-app purchases | Yes | Yes |
| Ads | No | No |
| Update frequency | Every 2 months | **Every 3 days** |
| Monetization | Free | — |
| Size | 123 MB | 71 MB |
| Requires iOS | 18.6 | **15.0** |
| Devices | iPhone, iPad | **iPhone, iPad, iPod** |
| Age rating | 4+ | 4+ |
| Developer | [Historycentral.com](https://appshunter.io/developer/1744330560) | [KHANH HA DANG](https://appshunter.io/developer/1894659816) |

## What reviewers say

### Plumbing Formulator

[App page](https://appshunter.io/ios/app/plumbing-formulator/id303497783)

This professional calculator app provides over 200 formulas, calculators, and reference materials for plumbers, HVAC technicians, and mechanical contractors. It covers a wide range of calculations for water flow, piping, drainage, water heaters, pumps, and more, all in one pocket-sized tool.

**Highlights:** Over 200 formulas and calculators, Water flow and supply calculations, Pipe and piping calculations, Drainage and venting calculations, Water heater and pump calculations, Reference charts and code books, Pipe cut list optimizer

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

**In-app purchases (4)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Pro Version | $1.99 | one-time |
| Pro Purchase | $3.99 | one-time |
| Starter | $5.99 | one-time |
| Growth | $9.99 | one-time |


### HomeKept

[App page](https://appshunter.io/ios/app/homekept-maintenance-planner/id6772906710)

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

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| HomeGuard Pro Monthly | $4.99 | per month |
| HomeGuard Pro Annual | $39.99 | per year |


## Frequently asked questions

### Is Plumbing Formulator free?

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

### Is HomeKept free?

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

### Do Plumbing Formulator or HomeKept have ads?

Neither Plumbing Formulator nor HomeKept shows ads.

### Which is updated more often, Plumbing Formulator or HomeKept?

Plumbing Formulator ships an update every 2 months, and HomeKept every 3 days. Most recently, Plumbing Formulator was updated on October 31, 2026 and HomeKept on November 5, 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.*