# HydroCalc Plus vs Volume in Pipe

The clearest difference is price: Volume in Pipe at Free against HydroCalc Plus's $3.99. Volume in Pipe also leads on in-app purchases (none vs 4). HydroCalc Plus's advantage is update cadence (every 3 weeks vs every 26 months) and device support (3 vs 1). On rating, ratings volume, ads and iOS requirement there is nothing between them.

Volume in Pipe is free to download; HydroCalc Plus costs $3.99 up front. HydroCalc Plus sells 4 one-off in-app purchases. Volume in Pipe asks for nothing beyond the download.

On the App Store both sit at effectively the same score — 5.0 for HydroCalc Plus against 5.0 for Volume in Pipe. Both are backed by a comparable volume of ratings — 1 and 1 respectively.

HydroCalc Plus ships an update every 3 weeks, Volume in Pipe every 26 months. The most recent releases landed on August 31, 2026 and September 10, 2026 respectively.

## The numbers

| Metric | HydroCalc Plus | Volume in Pipe |
| --- | --- | --- |
| Price | $3.99 | **Free** |
| Rating | [5.0 (1 ratings)](https://appshunter.io/ios/app/hydrocalc-plus/id578807688/reviews) | [5.0 (1 ratings)](https://appshunter.io/ios/app/volume-in-pipe/id1582068096/reviews) |
| Number of ratings | 1 | 1 |
| Positive reviews | 100.0% of reviews | — |
| In-app purchases | Yes | **No** |
| Ads | No | No |
| Update frequency | **Every 3 weeks** | Every 26 months |
| Monetization | Paid | **Free** |
| Size | 34 MB | 11 MB |
| Requires iOS | **15.1** | 16.6 |
| Devices | **iPhone, iPad, iPod** | iPhone |
| Age rating | 4+ | 4+ |
| Developer | [Transparent Blue Water LLC](https://appshunter.io/developer/1847968351) | [Kelly Gayneaux](https://appshunter.io/developer/1082576429) |

## What reviewers say

### HydroCalc Plus

[App page](https://appshunter.io/ios/app/hydrocalc-plus/id578807688)

A professional tool for hydraulic engineers to calculate pressure losses in piping systems. It supports US and SI units, offers an extensive pipe material and fittings database, and includes inverse calculations for design optimization.

**Highlights:** Friction head loss calculation (Hazen-Williams), US and SI unit support, Extensive pipe material library, Fittings and valves database, Inverse calculation mode, Real-time results (velocity, losses)

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

**In-app purchases (4)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Pump Power Calculator | $1.99 | one-time |
| System Curve Generator | $1.99 | one-time |
| Pipe Database | $1.99 | one-time |
| Industrial Fluids Pack | $2.99 | one-time |


### Volume in Pipe

[App page](https://appshunter.io/ios/app/volume-in-pipe/id1582068096)

Quickly estimate the gas volume within pipes, launchers, or vessels. Input operating conditions and pipe size for an approximate volume calculation. This tool is designed for rapid field estimates.

**Highlights:** Estimate gas volume, Input operating conditions, Select pipe size, Quick field estimates, Supports iPhone

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is HydroCalc Plus free?

HydroCalc Plus costs $3.99, and also offers in-app purchases.

### Is Volume in Pipe free?

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

### Which has better reviews, HydroCalc Plus or Volume in Pipe?

HydroCalc Plus and Volume in Pipe are both rated 5.0 out of 5 on the App Store, from 1 and 1 ratings respectively.

### Do HydroCalc Plus or Volume in Pipe have ads?

Neither HydroCalc Plus nor Volume in Pipe shows ads.

### Which is updated more often, HydroCalc Plus or Volume in Pipe?

HydroCalc Plus ships an update every 3 weeks, and Volume in Pipe every 26 months. Most recently, HydroCalc Plus was updated on August 31, 2026 and Volume in Pipe on September 10, 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.*