Qalculate/libqalculate

What is it?

Key features

• 01Unit calculations and conversion across SI, imperial, CGS and atomic units, plus daily-updated currency rates
• 02Symbolic calculation including factorization, differentiation, integration and solving equations
• 03Arbitrary precision with exact and approximate output
• 04Uncertainty propagation and interval arithmetic
• 05Over 400 customizable functions and built-in physical constants
• 06Command-line tool qalc with non-interactive and interactive modes, plus plotting via Gnuplot

Use cases

• Doing quick unit conversions or currency calculations from the terminal
• Performing symbolic algebra, calculus or equation solving without a full math package
• Calculating with measurement uncertainties in scientific or engineering work
• Embedding a full-featured math engine into another application through the library

Quick start

1. 1

   Build from the Git source: run autogen.sh

   ./autogen.sh
2. 2

   Configure the build (run automatically by autogen.sh)

   ./configure
3. 3

   Compile the project

   make
4. 4

   Install it as root

   sudo make install

Things to know

• !Requires GMP, MPFR, libxml2 and other libraries to be installed before compiling.
• !Git source builds also need automake and autoconf.
• !Plotting depends on the optional Gnuplot tool.

In collections

Topics

FAQ

What is libqalculate?

A cross-platform desktop calculator library and command-line tool supporting units, symbolic math, arbitrary precision and uncertainty propagation. Qalculate! is a multi-purpose desktop calculator built on libqalculate, a C++ library that powers its interfaces. It covers everyday tasks such as currency conversion and percent calculation, while also handling more advanced work like symbolic integrals and equations, arbitrary precision arithmetic, and interval arithmetic.

Is libqalculate free to use? What license does it have?

libqalculate is open source under the GPL-2.0 license. Check the license terms before using it in commercial products.

Is libqalculate still maintained?

Actively maintained. The last commit to libqalculate was on Nov 6, 2026.

What can I use libqalculate for?

Doing quick unit conversions or currency calculations from the terminal Performing symbolic algebra, calculus or equation solving without a full math package Calculating with measurement uncertainties in scientific or engineering work Embedding a full-featured math engine into another application through the library

How do I install libqalculate?

Build from the Git source: run autogen.sh: ./autogen.sh Configure the build (run automatically by autogen.sh): ./configure Compile the project: make Install it as root: sudo make install

Where can I get libqalculate?

The source code and installation instructions are on GitHub: https://github.com/Qalculate/libqalculate