SpeedCrunch
Open Source
SpeedCrunch is a high-precision scientific calculator featuring a fast, keyboard-driven user interface.
Soulver
Commercial
Soulver is quicker to use than a spreadsheet and smarter and clearer than a traditional calculator.
Qalculate!
Open Source
Qalculate! is a multi-purpose desktop calculator for GNU/Linux (and Mac OS).
Windows Calculator
Free
Windows Calculator is a software calculator included in all versions of Windows.
Compare OpalCalc with alternatives
Compare SpeedCrunch and OpalCalc and decide which is most suitable for you.
Compare Qalculate! and OpalCalc and decide which is most suitable for you.
Compare Windows Calculator and OpalCalc and decide which is most suitable for you.