# Humidity Calc — Check humidifier filters.

> Check humidifier filters. (iPhone/iPad app by Hiroaki Oosawa.)

- Source: https://appshunter.io/ios/app/humidity-calc/id6797133577 (this page in markdown: same URL + `.md`)
- Developer: [Hiroaki Oosawa](https://appshunter.io/developer/6797133579)
- Category: Utilities, Weather
- Price: Free
- Age rating: 4+
- Requires: iOS 17.6 · 38 MB
- Languages: American English, Japanese
- Released: 2026-08-31
- Data updated: 2026-09-22
- User reviews in markdown: https://appshunter.io/ios/app/humidity-calc/id6797133577/reviews.md

## What is Humidity Calc?

【Calculate Theoretical Relative Humidity】

A humidity calculation app for managing indoor humidity and checking humidifier performance.

Calculate the theoretical indoor relative humidity from the outdoor temperature, outdoor relative humidity, and your indoor temperature.

By comparing the calculated value with your hygrometer reading, you can estimate humidification performance and determine when a humidifier filter may need replacement.

This app does not measure humidity.

【Key Features】

• Calculate theoretical indoor relative humidity
• Compare calculated and measured humidity
• Check humidifier performance
• Estimate humidifier filter deterioration and replacement timing
• Support daily indoor humidity management

【Recommended For】

• Users of evaporative humidifiers
• Anyone who wants to check humidifier performance
• Anyone who wants to know when to replace a humidifier filter
• People managing indoor humidity during dry seasons
• Anyone who wants to compare theoretical and measured humidity

【What Is Theoretical Relative Humidity?】

This app calculates the theoretical indoor relative humidity by converting outdoor relative humidity based on the amount of water vapor and applying the indoor temperature.

Comparing the theoretical value with your hygrometer reading helps you evaluate humidifier performance and estimate whether the filter has lost efficiency.

Ideal for users who want a simple way to monitor indoor humidity and maintain humidifier performance.


## Version history (last 2 releases)

### 1.0.1 — 2026-09-20

Added support for devices running iOS 17.6 or later.
Improved app performance and stability.

### 1.0.0 — 2026-08-31

No release notes.

## Apps similar to Humidity Calc

| App | Rating | Price | Category |
| --- | --- | --- | --- |
| [Video Compressor + Reduce Size](https://appshunter.io/ios/app/video-compressor-plus-reduce-size/id6761250139) | — | Free | Utilities |
| [AI Media Converter: MP4 to MP3](https://appshunter.io/ios/app/ai-media-converter-mp4-to-mp3/id6758046544) | 5.0 (1) | Free | Utilities |
| [Calcy - Calculator App](https://appshunter.io/ios/app/calcy-calculator-app/id1031082909) | 4.8 (42) | Free | Utilities |
| [ZenBrowser \| Simple browsing](https://appshunter.io/ios/app/zenbrowser-simple-browsing/id994432864) | 3.5 (14) | Free | Utilities |
| [Decibel - Accurate dB Meter](https://appshunter.io/ios/app/decibel-accurate-db-meter/id1130936133) | 3.5 (475) | Free | Utilities |
| [MD Calculator](https://appshunter.io/ios/app/md-calculator/id6463897900) | 4.5 (78) | Free | Utilities |

## More apps by Hiroaki Oosawa

- [Drainage Tank Water Level Calc](https://appshunter.io/ios/app/drainage-tank-water-level-calc/id6798235033)
- [Sanitary Dft. Supt.](https://appshunter.io/ios/app/sanitary-dft-supt/id6799862269)

All apps by Hiroaki Oosawa: https://appshunter.io/developer/6797133579

---

*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 2026-09-22.*