Rechenwerk is the programmer calculator we always wanted in our pocket. Mix number systems in one expression, work in RPN like the HP-16C, and see every bit of your result.

HEX, BINARY AND DECIMAL. IN ONE LINE.
Write numbers the way an assembler reads them: $FF or 0xFF for hex, %1010 or 0b1010 for binary, @17 for octal, #42 for decimal — and mix them freely:
%10001 + $123 + 32 + $A3 = 503
A number without a prefix is read in the base you selected.

RPN LIKE THE HP-16C
• Stack lift, ENTER, x↔y, R↓, CHS — or switch to algebraic entry: 3 + 3 =, like any calculator, with a live result
• An unlimited stack that scrolls above X, or the classic four levels
• Tap a level to use it again, swipe it into X or away
• 16 registers with STO and RCL

EVERY BIT IN VIEW
• Word sizes from 1 to 64 bits; unsigned, 1's or 2's complement
• The value in HEX, DEC, OCT, BIN and as characters ('ILBM')
• A bit grid: tap a bit to flip it
• Drag across bits to read a field — its value and its mask, perfect for hardware registers
• Carry and overflow flags, rotate through carry, count bits, set / clear / test bits
• Float mode shows the IEEE-754 bits of a double

MADE FOR DAILY WORK
• Hold any number to copy it — hex and binary keep their prefix
• Paste into the display when the clipboard holds a number
• Undo and redo every step, even an accidental AC
• A tape of every calculation
• bswap, wswap, clz, ctz, bitrev, maskl / maskr and more in algebraic mode
• Portrait and landscape — and on a tablet the calculator scales to fill the screen

PRIVATE BY DESIGN
No account, no ads, no tracking. Rechenwerk works offline; nothing you calculate leaves your device.