Results are calculated after you run the solution with the Play button. They are displayed in the "Output" window. You cannot edit the output text, but you can select, copy and print it. You can use the toolbar over the "Output" window on the right. The left side contains some options for calculation. You can also use additional commands from the context menu, that is displayed with a right click in the "Output" window. Detailed description is provided further in this manual.


Calcpad can show the substitution of variables, before the answer:

x1 = (-b – √D)/(2∙a) = (-3 – √89)/(2∙4) = -1.55

For that purpose, you need to check "Substitution" over the output window. It makes the solution very easy to follow and review. This is important when calculations need to be checked by supervisors, teachers etc. It is a great advantage over the traditional worksheets where the actual formulas are usually hidden in cells.

If you do not need substitution, you can uncheck this option. Then the answer will follow the calculation formula immediately:

x1 = (-b – √D)/(2∙a) = -1.55


The number of digits k after the decimal point is specified. It is entered into the "Rounding" input box over the output window. The value of k can be between "0" and "15". If you enter "0", all results will be rounded to integer. If the value is less than "0" or greater than "15", the respective limit value is taken.

However, there are some potential problems. If the result is less than 10-k and you round it to k digits after the decimal point, the output will consist entirely of zeros. That is why, Calcpad uses some additional rules: If the output contains less than k significant digits after rounding, it is expanded up to k significant digits. However, if the number is small enough, it will be difficult to count the zeros after the decimal point. In such cases, the output is represented in floating point format with k digits. If the exponent of the number is greater than 2k, the faction part is truncated. In this way, the output becomes easier to read, still providing at least k + 1 significant digits. You can see several examples bellow, obtained for (k = 3).

  • 0.000001∙π = 3.14E-06
  • 0.001∙π = 0.00314
  • 0.1∙π = 0.314
  • 1∙π = 3.142
  • 1000∙π = 3141.593
  • 1000000∙π = 3141593

Rounding affects only the way in which numbers are displayed in the output. Internally, all numbers are stored with the maximum possible precision until the calculations are completed. That is why, if you print the output and try to repeat the calculations, with the numbers from the report, you can get a small difference. It is because of using the rounded values instead of the actual ones.


Calcpad does not simply calculate. It also builds a professional looking report out of your formulas. It automatically applies Html formatting, which is simple enough to be recognized by any other software like Word. That is why, there are some limitations. For example, division is rendered linearly (without a horizontal division line). The program also applies the following formatting:

  • Intervals are maintained automatically.
  • Variables are formatted with italic.
  • Multiplication operator "*" is replaced with "∙".
  • Exponentiation operator "^" is formatted with superscript.
  • Underscore "_" is formatted with subscript.
  • Square root function is replaced with "√  ".

Bellow are provided several examples for different cases of formatting:

Text Html
x    +    3 x + 3
x-3 x – 3
3*x 3∙x
x/3 x/3
x+3 * y x + 3∙y
sqr(x+3) x + 3
x_1^3 x13
sin(x) sin(x)

Html formatting makes the report easier for reading and checking than the respective plain text. You can also insert additional Html code inside the comments and it will affect the final appearance. That is how Calcpad code can be used for building professional Web applications.


You can scale up and down the text size in the output window by holding the "Ctrl" button and rolling the mouse wheel. Rolling forward scales up and backward scales down.


You can send the report to an output file in Html format. This file is different than the input file and cannot be modified with Calcpad. The idea is to create a hard copy of your calculations that everyone can view and print without Calcpad. Html files can be opened on any computer using a web browser or office program like Word.

You can save the output file by clicking the Save button over the output window. Select the output file name and click "Save".

A good alternative to Html is printing the report to a pdf file. It is another way to make a hard copy of your calculations. First, you have to install a pdf printer. There are a lot of free pdf printers over the Internet. The process of printing is not much different than any other printer. Detailed description of printing inside Calcpad is provided in the next topic.


You can print the output by clicking the PrintPreview button over the output window. Normally, printing is performed after the calculations are completed. When you click the button, a print preview dialog is displayed:


You can set the printing layout and margins. Click the Page Setup button to change the paper size and type. Finally, press the Print button. A standard printing dialog is displayed. Select the preferred printer and click "Print".


Printing in Calcpad uses the built-in functionality of Windows and Internet Explorer. The above screenshots may look differently on your computer, depending on the versions you use. Alternatively, you can right click in the output window and select "Print preview..." from the context menu. If you select "Print", you will skip the preview and proceed directly to printing.


You can copy the entire output at once by clicking the Copy button over the output window. Then you can paste it in any other program. If it supports Html, like Word, formatting will be preserved. Otherwise, it will be pasted as plain text.

Export to Word

You can open the output directly with Word by clicking the Word button. You must have it already installed on your computer, but it does not need to be started. This method is easier than Copy-Paste