General Help (website and calculators)

Many of these calculators include complex formulas that have been developed over hundreds of years (although ours have not taken that long!). Whilst most formulas are both useful and interesting to those of a theoretical bent, you don't need a comprehensive understanding to apply them. However, where we feel that additional information may be of special interest or use, we provide references to relevant publications.

Hard-Wired Data

Database information and 'help' text are both embedded in the source code in order to minimise the response times of our calculators (i.e. everything works in RAM {not ROM}).

Help Levels (according to your needs)

All our calculators include operational, context and technical help suitable for those with a basic understanding of the relevant subject. If this facility is insufficient to enable you to solve your problem or complete your understanding, please take full advantage of the calculator-specific pages accessible from the 'Technical Help' menu.

The 'GiGo' Principle

As with all hand written formulas, it is possible to enter any values you wish and yet still achieve an answer that, to all intent and purposes, whilst incorrect, remains appropriate for special purposes, e.g. negative values for mass or density. Many of the more experienced and gifted mathematicians manipulate formulas in this way to acquire a result that can be used out of context.

In order to accommodate this exploitation, CalQlata has adopted the "GiGo" principle which literally means; "garbage in - garbage out", for all its calculators. This means that your results ('Output Data') are only as good as the information entered ('Input Data').

As such, whilst our calculators trap 'fatal errors' they will have a go at every calculation they can issuing error messages or warnings for those in which they detect incompatible entries. You may, for example see that some of your results for a given calculation are given as an "infinity", 'NaN' (not a number) or unexpected zeros where your input data is normally considered incompatible with the formula(s) concerned, whilst others may produce acceptable results. CalQlata has adopted this approach to maximise flexibility and prevent unwanted lock-ups in the use of its calculators whilst entering data in an unusual sequence.

Calculator Specific Help

Where input and output variables are specifically referred to in these pages they are colour coded to reflect their status. This is not the case where such variables are included in general discussion topics.

Please visit Fluid Numbers and Fatigue's Technical Help pages on this website for examples of the detailed step-by-step assistance we provide for more complicated procedures.

Together with the help pages included in each calculator, the operational and technical help provided in this website should enable you to get the most from our calculators.

Self-Checking Calculators

Many of our calculators include an internal self-checking facility (e.g. 2ᴺᴰ Moment of Area). Where this is available, we will inform you on the calculator's dedicated website Technical Help page.

Programs to follow ...

We apologise in advance for references made to calculators that have yet to be released. We are simply indicating where you will eventually find the reference information or facility.


Over the years we have expanded numerous formulas that would be wasted gathering dust on our shelves so we have incorporated them on our site just in case somebody out there can find a use for them (menu item: 'Useful Stuff'). For example, whilst there are many sources for instructions on out how to differentiate one or two trigonometric functions, we have worked out virtually all of them ('Differentiation Trig').

We shall add to this list as time permits.


Our unique carbon steel properties table (see Materials menu) has been included in this website because of years of frustration searching for genuine strength and hardness property ranges for these materials in sources that were either incomplete, too specific or too vague.

Your Feedback

If you obtain answers you don't understand or can't accept, you are welcome to send an email to the contact address that you will find in Contact Us. We will respond on the website 'Q&A' page for the calculator concerned (see left-hand menu) as quickly as possible. In this way, all other customers will have access to your query and our response. Your personal details will not be displayed on the website. If we are unable to provide you with a definitive answer, we will let you know and provide whatever advice / redirection we can offer.

The first person to notify CalQlata of a genuine fault in a calculator will be issued with a corrected version free of charge. A note explaining the fault will be added to the dedicated website page for that calculator.

Minimum System Requirements

Important Note:
All calculators bought and downloaded directly from the site are single user (license) versions that have been designed to operate on personal/privately owned computers only.
They will not operate on company machines nor can they be networked.
Those wishing to install them on company machines must contact CalQlata directly for multi-user licence versions of the calculator(s) concerned.

Full administrator and registry rights to the PC on which you are installing the calculator.

PC or Laptop with Microsoft Windows XP or later operating system

.NET Framework 4.0 Client Profile or later

The disk space and memory requirements are between 0.25k and 0.5k so most computers should easily handle these calculators

This website should operate with equal efficacy and reliability in most recognised web-browsers, e.g.; Explorer, FireFox, Edge, Chrome, Opera, etc.

Please read How They Work before purchasing

These programs do not work on Apple Mac systems

If you would purchase CalQlata's products but only in Apple Mac compatible format, could you please let us know?


You will find the solution to all common problems concerning the purchase and installation of CalQlata programs below:

The most important thing to understand is that our contributors, both technical and administrative, provide their services free of charge in order to help individuals (including one-man companies) compete with the analytical muscle of larger companies.
Therefore, our calculators are deliberately designed for installation on privately owned, personal PCs to which the user has full (unrestricted) administration and registry rights.

Whilst larger (than one-man) Companies may purchase our calculators, this can only be done through direct contact with CalQlata for the purchase of multi-user licenses.

Problem Reason (for problem) Solution
Nothing happens after purchasing You should receive three emails within minutes of purchasing a program:
1) Security data for installation
One for each program purchased (CalQlata)
2) Late download instructions (CalQlata)
3) Receipt of Payment (PayPal)
but you may need to be a little patient
(the internet can be a little slow)
If you have not received either or both of your automatic emails from CalQlata immediately after purchasing, please contact us and we will see that you receive your purchased product(s) manually.
Can't download the program immediately after purchasing CalQlata will not have yet received PayPal's confirmation of payment
(PayPal can be a little slow)
You will receive late download instructions in an email from CalQlata {see Reason 2) above},
which will become active immediately after CalQlata has received confirmation of payment from PayPal
Problems downloading program(s) via a company server Company servers tend to block downloads they don't recognise Use your private internet access facility (at home)
Problems downloading program(s) "Response Buffer Limit Exceeded" The size of the product purchased has exceeded the response buffer limit on the customer's server. Contact CalQlata and we will send the product directly via email or DropBox.
You don't receive one or more of the above three emails after purchasing your program(s) There is no reason you shouldn't receive your emails Check 'Junk Mail' box,
or contact CalQlata
Installation Error: "Incorrect Key" The security key entered does not match the program name (e.g. typo) Reinstall the program⁽¹⁾ using the correct key code
Installation Error: "Incorrect Version" The security key entered does not match the version of the program (e.g. typo) Reinstall the program⁽¹⁾ using the correct key code
Installation Error: "Incorrect Licensee" The security key entered does not match the name of the Licensee (e.g. typo)
You are trying to install the program on a machine that is not owned by the Licensee
Reinstall the program⁽¹⁾ using the correct the key code and associated "First" and "Last" names
Installation Error: "Incorrect Licensee"
The keyboard used to enter your name at the time of purchase uses non-ANSI character codes. Notify CalQlata, who will generate a new security key for you.
Installed program will not open You have installed the program on a machine to which you do not have full administration and registry rights (i.e. a company machine) Uninstall the program and reinstall it on a personal computer to which you have full administration and registry rights
Advanced Installer error:
Stack Trace (x86)
You are trying to install the program on a network drive Uninstall the program and reinstall it on drive 'C:'

Program does not appear on the screen

Registry entries for FormX and FormY
Fig 1. Registry - Program Positioning

Occasionally Windows corrupts registry data, not just for CalQlata programs ...

If when opening a calculator the icon appears in your taskbar but the program does not appear on your screen, the program's window positioning data will have been corrupted. Windows will have changed these values to a location outside your screen, so they will have to be corrected manually.

There are two fixes for this problem:

Before you do anything, close the calculator, either using the icon in the taskbar, or press 'alt+ctrl+del', select 'Task Manager', select the calculator name and 'End Task'.

Option 1) Uninstall>Reinstall the calculator


Option 2) If you are comfortable working with the registry;

a. Type "regedit" in the box on your taskbar (bottom-left) and press the 'Enter' key
               [calculator-name] (Fig 1)
c. Double-click on "FormX" and change the value to 100
d. Double-click on "FormY" and change the value to 100
e. Close the registry

When you next open the calculator, it will appear on the screen.
After correction, the problem should not occur again until Windows decides otherwise.

Installation and operation instructions can be found on 'How They Work'

Searching this Site

Because the Google search engine is much better than anything we could provide, we suggest that you use it to find words or phrases on this site.
Moreover, because many of the expected search words and phrases appear in our menus we suggest that you qualify your search with the minus (-) facility together with the following book-ends; ">" & "<"

The following examples will find the designated words/phrases but exclude all pages that only include this phrase as a menu item:

designated phrase; 'plastic stress in beams'
Search Phrase: "plastic stress in beams" ->plastic stress in beams<:


designated phrase; 'plastic stress'
Search Phrase: "plastic stress" ->plastic stress in beams<:


designated words; 'plastic' or 'stress'
Search Phrase: plastic OR stress ->plastic stress in beams<:


  1. Always uninstall programs before reinstalling them; instructions can be found on How They Work