I'm looking for a calculator

  • that can calculate (basic operations +, -, *, / would suffice, more are welcome)
  • that can calculate including units (e.g. 2m² + 5000cm²)
  • can convert units (e.g. m to ft)
  • is gratis
  • works on Windows
  • starts up quickly and is easy to use

Ideally (but optional)

  • is portable

I do not want

  • a full-blown mathematics solution like Matlab, Mathematica or similar
  • What kind of Windows do you have ? – PROBERT Jun 29 '16 at 20:16
  • @PROBERT: Windows 7 SP1 x64. I used to add that to questions and use the Windows-7 tag, but often it was edited out, so I go with "Windows" since then. – Thomas Weller Jun 29 '16 at 20:21
  • If you upgrade to Windows 10, there is an app for that and has all kind of different app that use that microsoft.com/en-us/store/apps/unit-conversion/9wzdncrfj0pr Just thought I'd let you know. and here is another one you probably want to take a look at here howtogeek.com/136288/… – PROBERT Jun 29 '16 at 20:26
  • @PROBERT: Both look like it can convert but not calculate (e.g. (2300m²+5400m²)/2 in ft²) – Thomas Weller Jun 29 '16 at 20:37
  • 1
    You can do this with Wolfram Alpha. It has an offline mode but there is a limit on use before you have to start paying. – Chenmunka Jun 30 '16 at 8:41

I was happy with Phyxcalc for a long time. See another answer recommending Qalculate now.

I'm happy to have found Phyxcalc.

  • Physxcalc can calculate with units, just type them

  • can convert units with the -> operator

    2m²+5000cm² -> ft²
  • is gratis (freeware, exact license unknown)

  • works on Windows 95, 98, XP, Vista and 7 officially.
  • works on Windows 10 (Build 10586) on my VM as well.
  • startup time is less than 1 second on my second generation Intel i5
  • is portable (single executable + a few text files with unit definitions)
  • is easy to use: well, at least kind of. Entering formulas are quite straight forward as seen before. However, it starts with a completely empty UI that does not react on F1.

    Phyxcalc default UI

    It is possible to show a keypad using the context menu:

    Phyxcalc key pad

  • It appears to support only German. Is there any way to change it to English ? – Rohit Gupta Jun 30 '16 at 3:16
  • @RohitGupta: oops. I didn't notice. It seems there's an open source version at github.com/strahlex/PhyxCalc I need to have a look at that version. – Thomas Weller Jun 30 '16 at 4:30

Not many people seem to be aware, but Windows (10, at least) has some of these functions built in, with its Calculator.

From what I could tell, it doesn't seem to be capable of adding together units natively, but it does have the ability to convert between units, which can assist with calculations at a later stage.

Simply open up Calc(Search in the Start Menu) and click the little burger icon at the top left for many unit options:

Image showing calculator conversion options


Meanwhile I have replaced Phyxcalc with Qalculate, which has more features and a UI that is a bit more self-explanatory.

  • it's , GPL 2 license
  • it works on Windows 10 x64 1909 (official docs say it works from Vista)
  • startup time is ~ 2 seconds
  • download size is 51 MB, which is not exactly small. The largest thing about it is a 23 MB Unicode library (libicudt) which gives the nice graphical output.
  • the 32 bit version even exists as a portable version

One thing I wanted to change first is the settings to

[x] ignore system language

because it confused my to have the UI in English but enter decimal digits in German.

Let me give the same examples as I did for Phyxcalc:



For year, Phyxcalc uses yr and Qalculate uses year:

=157.788 MJ

Conversion is possible as well, but not that convenient to type (or I did not yet figure out how to type):

Example of unit conversion

And an example where the nice output is a bit more obvious (in dark mode):

Example of integration


Since version 0.12, Speedcrunch supports units as well.

  • it is , licensed under GPL
  • that can calculate including units (see screenshot below)
  • can convert units (see screenshot below)
  • works on Windows 10 (I tried, see screenshot below)
  • starts up quickly (hardly measureable)
  • is also available as a portable version


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