# HydroniCalc — 23 hydronic calculators

> 23 hydronic calculators (iPhone/iPad app by Eric Chmara.)

- Source: https://appshunter.io/ios/app/hydronicalc/id6796810526 (this page in markdown: same URL + `.md`)
- Developer: [Eric Chmara](https://appshunter.io/developer/1892404568)
- Category: Utilities, Productivity
- Price: Free with in-app purchases
- Age rating: 4+
- Requires: iOS 17.0 · 7 MB
- Languages: American English, Dutch, French (France), German (Germany), Italian, European Spanish
- Released: 2026-08-17
- Data updated: 2026-08-30
- User reviews in markdown: https://appshunter.io/ios/app/hydronicalc/id6796810526/reviews.md

## What is HydroniCalc?

HydroniCalc brings together 23 hydronic calculators for heating engineers and installers of water-based heating systems. Everything runs in metric units, offline, and without an account.

The calculators are grouped into four families:

• Basic hydraulics and pipework: power, flow and temperature difference, diameter and velocity, linear and fitting pressure losses.

• Valves, balancing and circulator: the Kv / flow / pressure-drop relationship, valve sizing, balancing, and the pump operating point.

• Pressurization, volumes and separation: fill pressure, water expansion, expansion vessel, and system volumes.

• Radiators and underfloor heating: radiator output correction, sizing, and underfloor loop length.

Each calculator shows the values to enter and displays the result as soon as the required data is valid. An info button explains the purpose of the calculation, the expected inputs, the method, the results, and the usage limits.

Built-in Kv tables: look up the Kv values published by manufacturers (manufacturer, product, and generation), then copy a value to paste into your calculation. The tables never fill a calculation automatically; the value is always typed or pasted into the field.

Recent calculations: your ten most recent successful calculations are stored locally, so you can find them again and resume them with their values.

Eleven calculators are free to use. A single, non-subscription purchase permanently unlocks the other twelve for the Apple account used. If a purchase isn’t recognized, “Restore Purchases” asks the App Store to sync it again.

## Pricing and in-app purchases

Base price: Free.

**One-time purchases**

| Purchase | Price | Type |
| --- | --- | --- |
| Unlock All Calculators | $12.99 | one-time |



## Version history (last 1 release)

### 1.0 — 2026-08-18

No release notes.

## More apps by Eric Chmara

- [Hi-Lo Card Counting Trainer](https://appshunter.io/ios/app/hi-lo-card-counting-trainer/id6762020688)
- [Clever Unicorns](https://appshunter.io/ios/app/clever-unicorns/id6799504831)

All apps by Eric Chmara: https://appshunter.io/developer/1892404568

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*Data collected daily from the US App Store and indexed by [AppsHunter](https://appshunter.io/). User reviews are verbatim App Store reviews. Ratings, prices and chart positions refresh continuously; this snapshot is from 2026-08-30.*