CalC ("Calcium Calculator") is a free (GNU copyleft) modeling tool for simulating intracellular calcium diffusion and buffering. CalC solves continuous reaction-diffusion PDEs describing the entry of calcium into a volume through point-like channels, and its diffusion, buffering and binding to calcium receptors.

New: CalC version 7.0 implements cooperative calcium buffers
New: CalC version 7.4 implements binary file output
New: CalC version 7.6 implements non-linear membrane pump
New: CalC version 7.7 implements spherical enclosures and obstacles
New: CalC version 7.7.2 implements space-dependent calcium uptake

CalC versions 6.x.x mirror versions 7.x.x, but allow simple buffers only, and therefore run faster; use them whenever cooperative buffers are not needed

Installation instructions: README

VersionCa2+ buffers: Source: Executables:
Version 7.7.4Mar 17, 2014 Cooperative UNIX MSDN C++ Win32 Cygwin OS X 10.8.5
Version 6.7.4Mar 17, 2014 Simple (faster code) UNIX MSDN C++ Win32 Cygwin OS X 10.8.5
[ Link to prior CalC versions and updates ]

Versions 7.8 and 6.8 to be released June 2015, featuring an updated numerical engine with improved implementation accuracy of non-rectangular diffusion volumes and diffusion obstacles.

CalC Features:
CalC is provided on an as-is basis. I will respond to any bug reports or technical questions, in due course. If you use CalC in your published work, please cite this URL ( or our 2002 Biophys J article, and please send me a reference for inclusion in the CalC publication list upon publication.

This work is supported in part by the National Science Foundation grants 0417416 and 0817703. However, NSF bears no responsibility for any findings, recommendations or conclusions provided by this material.
Last modified: Jun 5, 2014             Maintained by Victor Matveev