OpalCalc is described as 'Brand new type of calculator for the PC. As easy to use as Notepad or a word processor, OpalCalc allows natural language in the sum and multi-line support so you can go back and adjust your previous calculations on the fly' and is a Calculator in the education & reference category. There are more than 50 alternatives to OpalCalc for a variety of platforms, including Windows, Linux, Web-based, Mac and Android apps. The best OpalCalc alternative is SpeedCrunch, which is both free and Open Source. Other great apps like OpalCalc are Qalculate!, Numara Calculator, Numbat and Qaltex.
Kalk is a convergent calculator application built with the Kirigami framework. Although it is mainly targeted for mobile Linux platforms, it can also be used on the desktop.
Hissab is a simple and intuitive calculator, unit-convertor and productivity application.
A text calculator for natural language expressions, variables & unit conversions, with a vim-style TUI. Inspired by Numi.
The Unsure Calculator is an online tool that lets you calculate with numbers you’re not sure about.
Ever wanted to work something out, but your default calculator isn't powerful enough, and it's not worth creating a spreadsheet for?
Numbr is a currency calculator, a notepad that understands your calculation. You can use notes with numbers alongside each other. And all your numbers are instantly calculated as you type.
Calculist is an open source application that facilitates effective thinking. Write down your thoughts, ideas, and data in the form of lists. Focus your attention by zooming in to a specific list, and zoom out to see the broader context.
A kickass, open-source calculator that lets you do calculations and unit conversions naturally, with features like:
Do you really need your calculator's on-screen number pad? (You know, the virtual keyboard?)
Germany
EU
Czechia
Hungary
