Download THERMOCALC software

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This is the download page for THERMOCALC, a program by Roger Powell and Tim Holland.

You can learn more about THERMOCALC here. To fire up THERMOCALC for the first time, see the Get started guide. If you’ve used it before, and want files for thermodynamic input and controlling calculations, see the THERMOCALC download guide or main Downloads page.

Our current THERMOCALC is version 3.50. See below for legacy versions.


The current version of THERMOCALC 3.50 (tc350) dates from 21 December 2020.

Scripts have changed extensively since the previous release in January 2020. Scripts related to phase diagram calculations (calcmode 1) are documented in scripts-tc350.pdf, which is bundled with the download. For scripts related to other calculation facilities, refer to the relevant webpage.

THERMOCALC 3.50 is still referred to as “tc350beta”, to remind the development team that µ-µ calculations and some calculations with aqueous fluid still aren’t working. However, the December 2020 release is stable with respect to other calculation facilities.

All releases of tc350 expect the axfile format that is identified by “50” in the filename.

In our blog post announcing the latest release, we discuss the progress represented by the latest developments.

Latest versions current 21-12-2020:

For Mac, compiled under Intel x86-64 architecture (machines produced before Nov 2020):

For Mac, compiled under Apple Silicon (machines produced from Nov 2020):

For Windows, compiled under Windows 10:

For Linux, compiled under Ubuntu 18.04:

Legacy versions

Here we provide limited access to legacy versions of THERMOCALC. Please be aware of some key distinctions between version 3.50, version 3.47, and versions 3.46 and older:

Changes to results of calculations. The output of some calculations varies very slightly between versions 3.50, 3.47 and older versions. The differences are due to changes in (1) construction of non-dataset end-members from order-disorder end-members, for end-members with no compositional equivalent in the dataset, (2) application of ∆V terms to non-dataset end-members constructed from a single dataset end-member, and (3) precision of reference temperatures and pressures (273.15 K and 0.001 kbar in tc350; 273 K and 0 kbar in earlier versions).

Changes to axfile format. Versions 3.47 and 3.50 each require axfiles in a specific format, and are unable to read other formats. Versions 3.46 and older are unable to read axfiles in tc347 or tc350 format.


TC3.47 was first released in 2018 at the same time as the igneous set of HPx-eos. It requires its own axfile format, which differs from both tc350 and versions older than tc347. All sets of HPx-eos on this site are currently available in tc347-format, labelled with “47” in the file name.

Final versions:

THERMOCALC 3.46 and older

If you need a version of THERMOCALC that pre-dates 3.47, or axfiles in formats compatible with these older versions, contact us.