CalcPlus v.1.0 (RUS) / 2004 is an extended (by Microsoft) version of this calculator. Added values conversion option. (Only russian version available..)


[little offtop]
Old Microsoft CALC.EXE from Win 3.11 contains an "easter egg" - calculate 3.11-3.1 and see result)).
(It's WIN16 NE-EXE, then doesn't works on 64-bit new OS's, only on 32-bit new Windows).
[/little offtop]



--Add--

RSC 1.3 / 1991 & RSC 3.0 / 1993 - it's the best DOS programmers/scientifics resident calculator. More powerful than standard CALC.EXE from Windows.

I'm using (more often) simple DOS resident HEX/DEC calculator CALC.COM (remaked 2005) . But it's for amateurs..


--Add2--

Good functions, but It is sorry that on vbаsiс..
However thanks, - added into collection.

I also use speedcrunch. You can easily switch between using binary/decimal/hexadecimal for output (no restriction on input) and the best thing is it shows the result while you're still typing. It also has a bit level view which also updates on-the-fly.
screenshot

Best response yet!

Strong recommendation: IPython

Just type iPython in your iTerm or WSL or Konsole and use hex(), lol

Sometimes can be useful AnalogX PCalc.

I would recommend SpeedCrunch. It got syntax just like coding, easy-to-use.

I think, programmer, should write calculator himself :)
First of all, it is interesting and you can add features, required by your calculation style (e.g. reverse notation, if you love it), second, it is not a very difficult task.

p.s. surely, I wrote my favorite myself, here is list of features, maybe someone will find them useful to implement in their programs:
- almost any number lengths are supported, i.e. 128-bit numbers, 256-bit, etc.
- floating point numbers can be with different mantissa and exponent size, so one can just get 128-bit floating point compatible with IEEE-754, or play with 256-bit floats to see if they will help.
- all bit operations are supported, including popcount and cyclic shift even through carry bit (to emulate CPU instructions), but one can cyclic shift even 256-bit number too
- surely, hex, oct, bin radixes are supported, including limiting representation size, so one can always know how many bytes will be required to represent current number in memory (including floating point format)
- binary complement format is supported, one can change signed and unsigned representation on the fly, this is usefull to check, that e.g. -16=240 in byte types.
- full SNaN, QNaN, machine zero, epsilon, +Inf, -Inf and rounding schemes support for IEEE-754.
- some exotic functionality also presents: e.g. representing floating point number as a continuos fraction, checking for primeness, finding gcd/lcm, etc.

and so on... even if I missed smth required for my work, I just edit sources and add this functionality :)

p.p.s. not attached here, since calculator is a bit ugly and has no built-in help, and one should remember all its commands.

When most calculators hit an overflow you can depend on this one

http://mrob.com/pub/comp/hypercalc/hypercalc-javascript.html

Old DOS resident HEX/DEC calculator, remake of CALC.COM (c)D.Gurtyak,1990:
CALC.COM v.0.000a, remake 2005

Old DOS resident scientific calculator with reverse notation and minimum of memory requirements:
SCALC.COM v.1.0(fixed) (c)Safonenkov,1992

Both written on ASM.