# Calculate Comfort — Psychrometric calc: dew point

> Calculates atmospheric comfort levels using temperature, humidity, and pressure inputs. (iPhone/iPad app by JUN KANAYAMA.)

- Source: https://appshunter.io/ios/app/calculate-comfort/id605648449 (this page in markdown: same URL + `.md`)
- Developer: [JUN KANAYAMA](https://appshunter.io/developer/605648452)
- Category: Productivity, Weather
- Price: Free with in-app purchases
- Rating: 3.90/5 from 35 App Store ratings · 28 written reviews indexed
- Age rating: 4+
- Requires: iOS 16.0 · 13 MB
- Languages: American English, Arabic, French (France), German (Germany), Hindi, Indonesian, Italian, Japanese, Korean, Brazilian Portuguese and 8 more
- Released: 2013-02-26
- Data updated: 2026-08-30
- Monetization: free with in-app purchases
- User reviews in markdown: https://appshunter.io/ios/app/calculate-comfort/id605648449/reviews.md

## What is Calculate Comfort?

Calculate Comfort computes the psychrometric properties of moist air — dew point, wet bulb temperature, absolute humidity, enthalpy and more — from temperature and humidity. Turn a dial instead of reading a psychrometric chart. Built for HVAC design, instrumentation, building maintenance and condensation control.

Units: the Pro version switches the entire readout between IP and SI in one tap, °F⇄°C included. Useful when your measurements are in IP but the equipment data is in SI. If you work only in Fahrenheit, our companion app Psychrometer °F opens in Fahrenheit by default.

■ Who it's for
・HVAC engineers and contractors who need moist-air properties on site
・Technicians converting psychrometer readings to relative humidity
・Anyone assessing condensation or mold risk from dew point
・Students learning to read a psychrometric chart

■ What it calculates
Enter temperature plus relative humidity, dew point or wet bulb temperature:
・Relative humidity (%RH)
・Dew point (°C DP) / frost point (°C FP), switchable below 0 °C
・Wet-bulb temperature (°C WB)
・Mixing ratio, gravimetric absolute humidity (g/kg)
・Absolute humidity, volumetric (g/m³)
・Enthalpy (kJ/kg), for load calculations
・Specific volume (m³/kg)
・Vapor pressure and saturated vapor pressure (hPa)
・Discomfort index (DI)
・Estimated WBGT heat index (indoor, no solar load)
・Comfort indicator (18–28 °C, 40–70 % RH)

■ Main features
◯ Three input modes: relative humidity, dew point or wet bulb temperature. Tap the % icon to switch; keyboard entry also available.
◯ Works in place of a psychrometric chart. Dew point mode traces constant absolute humidity — sensible heating and cooling. Wet bulb mode traces the constant wet-bulb line — humidification and dehumidification.
◯ Three psychrometer types: aspirated (Assmann), wall-mounted (August) and sling. Below freezing you can set whether the wet bulb is iced; below −10 °C this applies automatically, except for the sling type.
◯ Pressure-corrected calculation: standard pressure (1013.25 hPa), built-in barometer, weather data or manual entry (800–1200 hPa).
◯ Automatic weather retrieval from your location, with a recommended indoor temperature (ASHRAE Standard 55). Choose OpenWeatherMap or Apple Weather.
◯ Works offline. A connection and location permission are needed only to fetch outdoor weather.
◯ Comfort indicator in color and emoji.

[Common gestures]
・Pressure and index readouts: tap to open settings
・Outdoor air (weather icon), dew point input, wet bulb input and reset buttons: touch and hold to open settings

■ Pro version (one-time in-app purchase)
・Removes all ads
・IP ⇄ SI unit switching in one tap: °C⇄°F, g/kg⇄gr/lb, g/m³⇄gr/ft³, kJ/kg⇄BTU/lb, m³/kg⇄ft³/lb, hPa⇄inHg
・Text export of calculation results
・Extended pressure input: 23–36 inHg
・Selectable saturation vapor pressure formula: Sonntag (WMO), Hyland-Wexler (ASHRAE), Wagner-Pruß (IAPWS-95), Goff-Gratch, Magnus-Tetens

■ Supported devices
iPhone with iOS 16.0 or later. Also runs on Apple M1 Mac (macOS 13.0 or later) and visionOS 1.0. Home Screen: ComfortCalc. App header: Psychrometer°Calc.

■ What it does not do
・Does not measure temperature or humidity with the device; outdoor values come from weather data
・Does not perform measured WBGT with a globe thermometer
・Does not draw a psychrometric chart

■ Calculation basis
・Saturated vapor pressure: Sonntag; other formulas in Pro
・Vapor pressure: JIS Z 8806
・Relative humidity and dew point: JIS and WMO; denominator over supercooled water
・Enthalpy: ASHRAE definition
・Recommended indoor temperature: ASHRAE Standard 55

■ Notes
Extreme input values increase error and may produce an error state. Rounding may shift the last digit when switching modes. Correctness of results is not guaranteed and no liability is accepted for damages arising from use.

Documentation, FAQ and calculation specs:
https://www7b.biglobe.ne.jp/~kanayama/PsychrometerCalc/

## Key features

- Calculates RH, Dew Point, Wet-Bulb Temp, Enthalpy, and more
- Visual comfort indicators with color and emoji
- Adjustable atmospheric pressure input
- Switchable between Discomfort Index (DI) and WBGT
- Automatic weather data fetching
- Unit conversion between SI and US units (Pro)
- Export calculation results as text (Pro)

## Pricing and in-app purchases

Base price: Free.

**One-time purchases**

| Purchase | Price | Type |
| --- | --- | --- |
| Pro Version | $3.99 | one-time |


## Recent user reviews (10 of 28)

All indexed reviews: https://appshunter.io/ios/app/calculate-comfort/id605648449/reviews.md

### 3/5 — 無料バージョン

*2026-07-17*

自宅療養中なので夏のエアコン推奨温度設定は助かっています

### 3/5 — Cannot Use Fahrenheit

*2025-07-25*

App works very well. It is disappointing one cannot change input to degrees F.

**Developer response:** Thank you very much for your valuable feedback!
We’re glad to hear that you find the app works well.
Regarding your request to use Fahrenheit: this feature is available by upgrading through an in-app purchase. Once activated, you will be able to easily switch between Celsius and Fahrenheit for temperature input.
We hope you will give it a try and enjoy an even more comfortable experience with our app!
Thank you for your continued support.

### 1/5 — As covers content

*2025-05-03*

The app is almost unusable because the banner ad covers the dry bulb temperature.

**Developer response:** Thank you very much for taking the time to share your feedback.

The app is designed so that the dry bulb temperature should not be covered by the banner ad. However, we will review this to ensure everything works as intended.
Additionally, by upgrading through an in-app purchase, you can remove all banner ads for an even smoother experience.
We hope you will give it a try and enjoy the app to its fullest.
Thank you for your support!

### 5/5 — よくできている

*2025-04-02*

かるーい気象の勉強にもなるのでは？！よくできているアプリだと思います。

### 1/5 — No f

*2024-07-31*

No  f

**Developer response:** Thank you for your comment. 
Please try Psychrometer °F

### 1/5 — Pro Version

*2024-02-04, version 4.1*

Unable to activate Pro version.

### 4/5 — Surface Temperature

*2024-01-02, version 4.1*

Isn’t there a place where we can write the surface temperature?

### 5/5 — Best simple calculator I have found!

*2023-02-26*

For calculating temperature, absolute and relative humidity and vapour pressure, this app does it with relative accuracy and then lets you email or text results. Easy input and user friendly.

**Developer response:** Thank you for using it😊

### 5/5 — 重量絶対湿度

*2022-10-16*

重量絶対湿度も追加していただけると、 ありがたいです！

→
気がつきませんでした。
ご回答有難うございます！

**Developer response:** ご利用ありがとうございます。😃
重量絶対湿度は、「混合比」g/kg として表示しております。
　絶対湿度は、容積絶対湿度g/m3を指すことが多く、世界的にも重量絶対湿度は、混合比と呼ぶ方が多いので、両者を区別するためそのような表示にさせて頂いております。

### 5/5 — 宜しく‼️

*2021-07-20*

これから使用して行きます。宜しくお願いします。どうも有難う御座います❣️

## Frequently asked questions about Calculate Comfort

### Does Calculate Comfort have ads?

Yes, Calculate Comfort contains advertisements. Users can remove these ads by purchasing the Pro version of the app.

### What is the price of Calculate Comfort?

Calculate Comfort is available for free. There are optional in-app purchases for Pro features, such as ad removal and unit conversion.

### What devices does Calculate Comfort support?

Calculate Comfort is currently supported on iPhone devices. Information regarding support for other Apple devices or Android is not specified.

### How often is Calculate Comfort updated?

The latest version of Calculate Comfort is 5.2, last updated on February 10, 2026. This indicates a recent update, suggesting the app is actively maintained.

### What is the age rating for Calculate Comfort?

Calculate Comfort has an age rating of 4+. This means it is suitable for users aged 4 and older.

### Can I export my calculations from Calculate Comfort?

Yes, the Pro version of Calculate Comfort offers an export function. This allows users to export their calculation results as text.

### How does Calculate Comfort handle different atmospheric pressure inputs?

Calculate Comfort allows users to select from Standard pressure, use the device's sensor, fetch weather data automatically, or manually enter values between 800–1200 hPa.

### What user sentiment is reflected in Calculate Comfort's rating?

Calculate Comfort has a rating of 3.9 stars from 33 ratings. This suggests generally positive user reception, though there is room for improvement.

## Version history (last 5 releases)

### 5.7 — 2026-08-27

• Added a link to the support page.
• Improved the main screen layout for the paid Pro version.

### 5.6 — 2026-07-26

- Fixed an issue where comments in the Comfort Popup were not displayed correctly.
- Other minor improvements.

### 5.5 — 2026-07-02

• Fixed a bug that switched the app into test mode while acquiring outdoor air (temperature). Other minor bugs were also fixed.
• When the atmospheric pressure mode is set to [Sensor] or [Weather], tapping the [Outdoor Air] button now retrieves it automatically.
• You can now choose the saturation vapour pressure formula. (Pro)
  Sonntag (WMO) / Hyland-Wexler (ASHRAE) / Wagner-Pruss (IAPWS-95) / Goff-Gratch (classical) / Tetens (WMO approximation)
  In normal use the results differ very little. These formulas were built in for verification during development and are now available.

### 5.4 — 2026-06-12

・Added a Comfort Screen.
You can now view the recommended indoor temperature based on the current outdoor temperature and humidity. (ASHRAE Standard 55)
You can also check the suggested heating and cooling target temperatures, quick tips on ventilation, dehumidification, humidification, mold prevention, and dryness, as well as alerts for heat and sudden temperature changes — all in one place.
・You can now choose a wallpaper. Select from Silver, Gold, Copper, Stone, Wood, or Glass.

### 5.3 — 2026-05-13

Added automatic switching for the WBGT heat stress index.
Fixed issues with text export in the Pro version and added multilingual support.
Improved the UI.

## Apps similar to Calculate Comfort

| App | Rating | Price | Category |
| --- | --- | --- | --- |
| [Mi Ruta Ciat](https://appshunter.io/ios/app/mi-ruta-ciat/id1577546460) | — | Free | Productivity |
| [Alky Pro](https://appshunter.io/ios/app/alky-pro/id1112394020) | — | Free | Productivity |
| [Focus Data Info App](https://appshunter.io/ios/app/focus-data-info-app/id1635266220) | — | Free | Productivity |
| [Binamod \| Earthquake](https://appshunter.io/ios/app/binamod-earthquake/id1609201360) | — | Free | Productivity |
| [G-CAMP](https://appshunter.io/ios/app/g-camp/id1581903560) | — | Free | Productivity |
| [Norges Vær](https://appshunter.io/ios/app/norges-vr/id1561170600) | — | Free | Productivity |

## More apps by JUN KANAYAMA

- [Psychrometer °F](https://appshunter.io/ios/app/psychrometer-f/id650395794)
- [One-Tap Home Alert](https://appshunter.io/ios/app/one-tap-home-alert/id672566579)
- [DogRun - Avoid bones](https://appshunter.io/ios/app/dogrun-avoid-bones/id908597369)
- [PetsAge](https://appshunter.io/ios/app/petsage/id1275858030)
- [マンション管理士 一問一答 過去問730問](https://appshunter.io/ios/app/730/id6450958511)

All apps by JUN KANAYAMA: https://appshunter.io/developer/605648452

---

*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.*