Arbitrary-precision unit-aware calculator with support for complex numbers, variables, and unit conversions
fend is a command-line calculator that performs arbitrary-precision arithmetic using rational numbers while tracking units throughout calculations. It supports unit conversions across SI, US customary, UK customary, and historical unit systems, allowing calculations like converting feet to centimeters or Celsius to Fahrenheit while maintaining precision.
The calculator includes full support for complex numbers, trigonometric functions, and variables for storing intermediate results. It can handle multiple number bases (binary, octal, hexadecimal, and bases 2-36), D&D-style dice rolls, and lambda calculus expressions. The CLI interface provides Emacs-style shortcuts for navigation and editing.
Developers, engineers, scientists, and students would find fend useful for precise calculations that require unit awareness and arbitrary precision. The tool is available as both a REPL for interactive use and a web interface, with the core functionality also packaged for integration into other applications through WebAssembly bindings.
# via Homebrew
brew install fend
# via Cargo
cargo install fend
# via Winget
winget install fend