Comparison

Kalkulilo (Calculator) vs HVAC Psychrometric Plus

Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.

Head to head
About

Kalkulilo (Calculator)

This app offers a versatile calculator with multiple modes, including scientific, bitwise, statistical, trigonometric, base conversion, and time calculations. It features a simple mode with large buttons and customizable interface. Widgets for notification center and Apple Watch are also included.

Highlights
  • Scientific calculator functions
  • Bit/integer mode with logical operations
  • Statistical calculations
  • Base/radix conversion (2-36)
  • Time value calculations
  • Customizable interface
  • Apple Watch app and widget
Features
Read full description

Kalkulilo is a comfortable calculator program and offers several different modes. - The scientific mode offers all the usual functions and operations like the basic arithmetical operations, power, logarithm, roots, trigonometry etc. - The bit/integer mode offers logical operations (AND, OR, XOR, >>, etc.) on bit level. All values can be displayed as binary, octal, decimal or hexadecimal numbers. Calculations can be done in 8, 16 32 or 64 bits. - In the statistics mode you can create a sample by adding several values and then calculate mean, median, quantil values, variance, standard deviation, range etc. - Trigonometry mode provides lots of trigonometric functions, including legacy ones - The base/radix mode allows you to do calculations with numbers of base 2 to base 36 - The Time mode lets you directly work with time values (hours, minutes seconds) - A simple calculator is also included, with just the basic operators and large buttons. The user interface can be customized, you can change the key colors for different categories of functions and operators which helps to distinguish and find these more easily. The App also includes calculator widgets for the homescreen which allows to do calculations directly from your homescreen and a calculator for the Apple Watch.

About

HVAC Psychrometric Plus

Perform single-state and mixed-air psychrometric calculations quickly and easily. Select input parameters and view updated results on a single screen. Supports 23 input combinations and offers email/spreadsheet export.

Highlights
  • Single-state psychrometric calculations
  • Mixed-air psychrometric calculations
  • 23 input parameter combinations
  • Real-time result updates
  • Universal app for iPhone and iPad
  • Email and spreadsheet export
Features
Read full description

The "HVAC Psychrometric Plus" app is the #1 selling psychrometric application for the Apple iPhone and iPad. Thousands of happy users have downloaded this useful application for performing quick and simple psychrometric analysis. Just a few reasons why you should buy this application: 1. The Psych Plus is a universal app that it is optimized for the iPhone and iPad. 2. This app was developed by Carmel Software, a company that has been developing software for 25+ years. We are experts in software design and HVAC analysis. 3. It allows you to easily perform single-state and mixed-air HVAC psychrometric calculations. 4. Select and update all input parameters and view the calculated results all in the same screen without switching from one screen to another. 5. Select from 23 different combinations of any 2 input parameters such as "Humidity Ratio / Dewpoint Temperature" and much more. 6. Immediately view updated results as you change the input values using the on-screen slider control. You can specify how much to increase or decrease values as you slide the indicator along the slider mechanism. 7. Send an HTML email and a spreadsheet attachment of all of the single-state and mixed-air inputs and results This application contains two separate input modes. The 1st input mode is the "Single-State" mode that allows you to specify 2 psychrometric parameters for a single stream of air and view the remaining 6 calculated values. You can quickly toggle through 23 different combinations of the 2 input parameters and instantly view the calculated results, all on the same screen. The 2nd input mode is the "Mixed-Air" mode that allows you to specify 2 psychrometric parameters for each of two air streams to calculate the mixed air psychrometric conditions. Once again, you can toggle through 23 combinations of the 2 input parameters and view all results in one screen. The following input and output value-types are displayed: 1. Dry-bulb temperature 2. Humidity ratio 3. Relative Humidity 4. Wet-bulb temperature 5. Partial pressure 6. Enthalpy 7. Specific volume 8. Dewpoint temperature 9. Total airflow or mass flow (for mixed-air calcs, only) You can specify additional parameters such as the altitude of the air being analyzed, the atmospheric pressure, different types of units such as degrees F or R, and English or Metric units. The "HVAC Psychrometric Plus" application was designed by Carmel Software Corporation, a leader in HVAC design software since 1995. In fact, Autodesk (the makers of AutoCAD) acquired our analysis software and incorporated it into their leading Autodesk Revit software product. In addition, ASHRAE has hired Carmel Software to develop custom mobile apps to accompany their various standards. We also offer the following apps for the iPhone/iPad: 1. HVAC Residential Load Calcs 2. HVAC Load Plus 3. HVAC Duct Sizer 4. HVAC Pipe Sizer – Gas Low Pressure 5. HVAC Pipe Sizer - Gas High Pressure 6. HVAC Pipe Sizer – Liquid 7. HVAC Pipe Sizer – Steam 8. Steam Tables 9. HVAC Toolkit 10. Psychrometric LT 11. HVAC Pipe Sizer Plus 12. HVAC Pipe Sizer Gas Plus 13. HVAC Quick Load 14. HVAC ResLoad-J 15. HVAC Equipment Locator 16. HVAC Psych HD

Screenshots

Kalkulilo (Calculator)4 screens
HVAC Psychrometric Plus4 screens

Verdict

The call

The clearest difference is rating: Kalkulilo (Calculator) at 4.5 against HVAC Psychrometric Plus's 3.0. Kalkulilo (Calculator) also leads on price ($2.99 vs $6.99) and update cadence (every 2 months vs every 6 months). HVAC Psychrometric Plus's advantage is chart position (#182 vs unranked). On review sentiment, ads, in-app purchases and device support there is nothing between them.

Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS

CostPrice · In-app purchases · Ads · Monetization

Kalkulilo (Calculator) costs $2.99 and HVAC Psychrometric Plus $6.99 up front. Kalkulilo (Calculator) sells 1 one-off in-app purchase and HVAC Psychrometric Plus sells 1 one-off in-app purchase. Whichever you choose, the download price is not the number that matters.

ReceptionRating · Positive reviews · Number of ratings

Kalkulilo (Calculator) holds the better App Store score, 4.5 against 3.0. That said, the two scores are not equally well evidenced: Kalkulilo (Calculator) has 29 ratings behind it against 2, so its average is the more settled of the two. Written reviews point the same way: 76% of Kalkulilo (Calculator)'s written reviews are positive against 73% of HVAC Psychrometric Plus's.

UpkeepUpdate frequency

Kalkulilo (Calculator) ships an update every 2 months, HVAC Psychrometric Plus every 6 months. Both last shipped on November 10, 2026.

Scorecard6 real differences · 5 level
Kalkulilo (Calculator) versus HVAC Psychrometric Plus: the parameters behind the verdict, then further details
ParameterKalkulilo (Calculator)HVAC Psychrometric Plus
Price$2.99 — better$6.99
Rating4.5 (29 ratings) — better3.0 (2 ratings)
Positive reviews75.8% of reviews — better72.7% of reviews
Number of ratings29 — better2
Update frequencyEvery 2 months — betterEvery 6 months
AdsNoNo
In-app purchasesYesYes
MonetizationFree with in-app purchases — betterPaid
Best chart rank—#182 — better
DevicesiPhone, iPad, Apple Watch — betteriPhone, iPad
Requires iOS16.0 — better17.0
Further details — not scored
Size3 MB1 MB
Age rating4++4
DeveloperAlexander ClaussCarmel Software Corporation

Customer experience

Kalkulilo (Calculator)

All ratings29 ratings
Positive86.2%
Neutral6.9%
Negative6.9%
Written reviews438 reviews
Positive75.8%
Neutral5.9%
Negative18.3%

HVAC Psychrometric Plus

All ratings2 ratings
Positive50.0%
Neutral0.0%
Negative50.0%
Written reviews11 reviews
Positive72.7%
Neutral0.0%
Negative27.3%

Bugs and requests

Kalkulilo (Calculator)

Reported bugs

3 issues
  • Number doesn't transfer correctly when switching between modes
  • Negative exponents not displayed correctly in engineering notation
  • Loses calculation history when changing modes

Requested features

5 requests
  • Add calculus, linear algebra, and probability functions
  • Implement a 'repeated equals' function
  • Add a backspace/delete button
  • Allow customizing color scheme
  • Improve Apple Watch integration

HVAC Psychrometric Plus

Not enough reviews yet to summarise bugs or requests.

In-app purchases

1 purchases

Kalkulilo (Calculator)

One-time1
  • Remove Ads$0.99
1 purchases

HVAC Psychrometric Plus

One-time1
  • HVAC Equipment Locator$9.99

Questions

Is Kalkulilo (Calculator) free?
Kalkulilo (Calculator) costs $2.99, and also offers in-app purchases.
Is HVAC Psychrometric Plus free?
HVAC Psychrometric Plus costs $6.99, and also offers in-app purchases.
Which has better reviews, Kalkulilo (Calculator) or HVAC Psychrometric Plus?
Kalkulilo (Calculator) is rated higher. Kalkulilo (Calculator) averages 4.5 out of 5 from 29 ratings, while HVAC Psychrometric Plus averages 3.0 from 2 ratings.
Do Kalkulilo (Calculator) or HVAC Psychrometric Plus have ads?
Neither Kalkulilo (Calculator) nor HVAC Psychrometric Plus shows ads.
Which is updated more often, Kalkulilo (Calculator) or HVAC Psychrometric Plus?
Kalkulilo (Calculator) ships an update every 2 months, and HVAC Psychrometric Plus every 6 months. Most recently, Kalkulilo (Calculator) was updated on November 10, 2026 and HVAC Psychrometric Plus on November 10, 2026.

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