World Calculator

World Calculator is a feather-light calculator designed as a clone of the Windows 7 Calculator. It comes equipped with standard math functions and gives you the possibility to copy results to the Clipboard.

Clear-cut GUI for standard math operations

The software application is packed in a simple interface which consists of a small window with a plain design and neatly structured layout, where all math functions are made visible.
Apart from performing additions, subtractions, divisions and multiplications, you can use percent, inverse number and square root operators, along with memory functions: adding and subtracting the current value from the stored value in the memory register, as well as recalling and clearing the memory register. The displayed value can be copied to the Clipboard with the click of a button from the "Edit" menu.

No setup required, besides .NET Framework

The entire program's wrapped in a single .exe file that you can save to a custom location on the disk or copy to a USB flash drive to seamlessly run World Calculator on any computer.
Just keep in mind that .NET Framework must be installed, otherwise it won't work. On the other hand, it doesn't create files on the disk without asking for your permission, or add new entries to the Windows registry.

Evaluation and conclusion

We haven't experienced any stability issues in our tests, thanks to the fact that the utility didn't freeze or crash. It executed calculations instantly while remaining light on system resources consumption. However, it displayed an error message on a couple of occasions when attempting to perform illegal operations.
To sum it up, World Calculator is a simple and straightforward desktop app for quickly making calculations using standard math operators and functions. Plus, it's free and open-source. No recent updates have been made, though.