Powerful GUI Calculator for Linux?
Most famous ones are:
- Gnome Calculator
- galculator
- xcalc
- kcalc
They all have basic and scientific modes.
By default Ubuntu comes with "Gnome calculator" unless you are using a specific flavor of Ubuntu.
Gnome Calculator:
For example in "Kubuntu" you should have "kcalc".
Kcalc:
galculator
There are other options available too like "xcalc", I use galculator
myself, install it using:
sudo apt install galculator
It's lightweight and really fast, doesn't have much dependencies, easy to use and has nice features.
Paper Mode:
Scientific view:
Extcalc
If you are looking for something with more features then I guess you are looking for "Extcalc".
I am personally a fan of speedcrunch, because it has a decent list of common physical and chemical constants and remembers your history across sessions:
As noted in the comments by @Michael:
[It is also] easy to mix/convert hex, bin and decimal representations of numbers. With mask() and unmask() it’s also possible to reduce/extend numbers to certain bit widths.
If your calculations involve units, such as with physics or electronics equations, I would recommend Qalculate.
It supports using units in expressions, so you do not have to worry about unit conversions manually. It is also a good check for whether you have typed the correct equation (this is called Dimensional analysis).