RPN Calculator Help
This calculator uses Reverse Polish Notation (RPN). Enter numbers, then apply operations. The stack shows the bottom at the top and X (top of stack) at the bottom, HP-style.
Basics
- Type a number into the entry field and press Enter to push it to the stack.
- Binary ops (+, −, ×, ÷) operate on Y and X (the top two stack values) and push the result.
- Stack ops: Swap (swap top two), Drop (remove X), Clear (clear stack and entry).
- Keyboard: Enter pushes or runs a command; +, -, *, / perform arithmetic on the stack.
Modes
- Basic: +, −, ×, ÷, Swap, Drop, Clear.
- Scientific: sin, cos, tan, sinh, cosh, tanh, sin⁻¹, cos⁻¹, tan⁻¹, sinh⁻¹, cosh⁻¹, tanh⁻¹, ln, log10, eˣ, sqrt, ∛x, x², x³, 1/x, y^x, x√y, x!. Angle mode button (RAD/DEG/GRAD) on the keypad (visible only in Scientific mode) affects circular trig input and inverse circular trig output (default RAD).
- Programmer: 32-bit integer ops: AND, OR, XOR, NOT, NOR, NAND, XNOR, SHL (««), SHR (»»).
Commands in the entry
You can also type command names instead of numbers and press Enter to execute them.
- Basic: +, -, *, /, swap, drop, clear, enter
- Word aliases: plus/add/addition, minus/subtract/subtraction, times/multiply/multiplication, divide/division/over
- Scientific: sin, cos, tan, sinh, cosh, tanh, asin, acos, atan, asinh, acosh, atanh, ln, log, log10, exp, sqrt/root, cbrt/cube root/cuberoot/∛, inverse/inv/1/x/recip/reciprocal, square/sq/x^2, cube/cubed/x^3/x³, pow/^/y^x, nroot/nthroot/rootn/xrooty/x√y, factorial/fact/!/n!/x!
- Programmer: and/& , or/| , xor , not/~ , nor , nand , xnor , shl/«« , shr/»»
- Angle: deg (switch to degrees), rad (switch to radians), grad (switch to gradians)
View modes
- Horizontal: single-column layout (default).
- Vertical: two columns split 50/50; left shows stack and entry (entry at the bottom), right shows buttons.
Skins
- Use the Skin dropdown in the top bar to switch between these looks:
- Green (classic CRT)
- Amber (1980s amber phosphor)
- Windows 3.1 (light gray, navy accents)
- Apple (Modern) — light, clean, blue accents
- Commodore 64 (blue background, light blue text)
- BSOD (blue screen, white text)
- USSR NIXIE (1970s Nixie tube orange glow)
- Sinclair LED (early Sinclair Cambridge LED)
- HP-48SX LCD (dot-matrix green/gray LCD)
- Sonnet 18 (Shakespeare parchment & ink)
- Your selected Skin is remembered via localStorage (key: rpn.skin).
Tips
- Use y^x for powers: push y, then x, then press y^x.
- Domain checks apply (e.g., sqrt of negative, ln of non-positive, asin/acos outside [-1,1]) and show a brief status message.
- Programmer ops coerce values to 32-bit signed integers; shift counts use b & 31.
- Your selected Mode, View, and Skin are remembered between sessions using localStorage (keys: rpn.mode, rpn.view, rpn.skin).