HumidCalc
HumidCalc Summary
HumidCalc is a ad-supported iOS app in Weather by yoshihito sakagami. Released in Jul 2016 (9 years ago). It has 1.00 ratings with a 5.00★ (excellent) average. Based on AppGoblin estimates, it reaches roughly 3.00 monthly active users and generates around $<10K monthly revenue (0% IAP / 100% ads). Store metadata: updated Mar 3, 2026.
Data tracking: SDKs and third-party integrations were last analyzed on Feb 13, 2025.
Store info: Last updated on App Store on Mar 3, 2026 .
5★
Ratings: 1.00
Screenshots
App Description
＊Weather data supported＊
A versatile humidity calculation app for everyone from general users to engineers — also suitable for agricultural applications.
This app allows you to easily calculate indicators such as the Discomfort Index, WBGT (estimated heat stress index), Volumetric Absolute Humidity (an important indicator for influenza prevention), and Humidity Deficit (HD) used in agriculture, using weather data.
You can also calculate a wide range of air properties from dry-bulb temperature (normal air temperature) and wet-bulb temperature obtained from ventilated psychrometers such as the Assmann psychrometer.
Atmospheric pressure can be entered manually.
The app supports 11 indicators across 15 calculation items, and unit conversion between Celsius/Fahrenheit and SI/Imperial units can be performed instantly by switching the temperature unit setting.
■ High-Precision Calculation Engine
This app uses the Wexler–Hyland equations combined with numerical analysis, enabling highly accurate and stable calculations across a wide range of environmental conditions.
■ Calculable Indicators
* Dew Point Temperature
* Frost point temperature
* Relative Humidity
* Humidity Ratio(Absolute Humidity)
* Mass-based absolute humidity
* High-resolution mass-based absolute humidity
* Volumetric absolute humidity
* Humidity Deficit (HD)
* Vapor Pressure Deficit (VPD)
* Enthalpy
* Specific Volume
* Saturation Vapor Pressure
* Water Vapor Partial Pressure
* Boiling Point of Water
* WBGT (Estimated value)
* Discomfort Index (DI)
Supplementary Notes on WBGT & Discomfort Index
Outdoor WBGT is defined as:
WBGT = 0.7 Tnw + 0.1 Td + 0.2 Tg (°F)
Since globe temperature (Tg) is not an input parameter, it is estimated from dry-bulb temperature (Td) using:
Tg = 1.45 Td − 27.162 (°F)
Td and Tg show a strong correlation (n = 17,376, R² = 0.919).
Natural wet-bulb temperature (Tnw) is obtained by converting the measured wet-bulb temperature from an Assmann psychrometer to natural conditions, assuming a wind speed of 0.5 m/s (1.64 ft/s) or less.
Details of this conversion algorithm are omitted.
The Discomfort Index (DI) is calculated as:
DI = 0.4 × (Td + Tw) + 15 (°F).
■ Weather Data & Sensors
By tapping the Weather Data button, you can obtain current atmospheric pressure, dry-bulb temperature, and wet-bulb temperature.
On devices equipped with a