FactSage
What is FactSage?
FactSage is a software package for predicting thermodynamic equilibrium states in multicomponent systems. When substances are placed in a closed vessel and brought to a specified temperature and pressure, chemical reactions and phase transformations occur. FactSage predicts the identity and quantity of all species present once the system has reached thermodynamic equilibrium. The software provides extensive functionality for computing phase diagrams of oxide systems and alloy systems, constructing Pourbaix (Eh–pH) diagrams, and developing the thermodynamic databases required for these calculations. Please refer to the Basic Application Examples and Advanced Application Examples for illustrative case studies. In recent years, additional modules have been incorporated for estimating the viscosity of molten slags and glasses, the viscosity and surface tension of molten alloys, and the thermal conductivity of compounds.
Computational methods for determining phase diagrams have been an active area of research for many decades. Approximately 50 years ago, the CALPHAD (CALculation of PHAse Diagrams) method emerged as a particularly promising approach and continues to evolve to this day. The CALPHAD method draws not only on thermodynamic theory and computational science, but also on an extensive body of experimental data — including enthalpies of formation, isobaric heat capacities, phase boundary compositions, and other quantities related to the Gibbs energy — accumulated through the enormous time and effort invested by researchers worldwide. FactSage provides a powerful platform through which the outstanding achievements of the CALPHAD community can be readily leveraged.
Benefits of Using FactSage

In modern R&D environments, the ability to apply chemical thermodynamics to deeply understand and predict complex phenomena is often critical to success.
Common Challenges in the Field:
- Troubleshooting Unresolved Issues: Investigating and mitigating problems such as mysterious deposits inside processing units or unexpected material corrosion.
- Predicting Material Behavior: Foreseeing the exact state and phase of newly developed materials under their actual operating conditions (specific temperatures and pressures).
- Optimizing Industrial Processes: Gaining a detailed understanding of the dynamic behavior of molten steel and slag to improve steelmaking efficiency.
Traditionally, researchers addressed these challenges by manually cross-referencing thermodynamic data tables with spreadsheet software to predict chemical reaction directions or determine substance concentrations at thermodynamic equilibrium. Alternatively, they relied heavily on printed alloy phase diagram collections to analyze material states.
While these traditional methodologies are fundamentally sound, calculating compositions and chemical activities in multicomponent systems requires an immense amount of manual labor and time. Furthermore, estimating phase diagrams for multicomponent systems or specific temperatures not covered in standard literature is exceptionally difficult.
The FactSage Solution
FactSage bridges this gap as a powerful, comprehensive software solution designed to quantitatively predict the thermochemical equilibrium states of complex multicomponent systems.
Because a single equilibrium calculation is completed in mere seconds to a few minutes, researchers can seamlessly perform rapid trial-and-error iterations—dynamically altering parameters such as material composition, temperature, pressure, and gas atmospheres.
With FactSage, you can perfectly replicate real-world chemical phenomena on your PC. By simulating and predicting states under altered conditions, evaluating countermeasures and process improvements becomes remarkably straightforward. Additionally, you can generate custom multicomponent phase diagrams across a wide spectrum of temperature and composition variables, significantly accelerating your material development timeline.
Key Features
- Highly Reliable Thermodynamic Databases: FactSage enables accurate equilibrium predictions across an exceptionally wide range of systems. Supported materials include metal oxides, carbides, nitrides, sulfides, salts, iron alloys, copper alloys, light alloys, precious metal alloys, rare earths, solders, nuclear materials, chemical fertilizers, and aqueous solutions. FactSage high-temperature oxide databases, in particular, are globally renowned for their industry-leading accuracy.
- Intuitive User Interface: The software offers outstanding operability (see Operation Example 1 and Operation Example 2). Users can effortlessly configure complex calculation parameters and visualize results through high-quality graphical plots.
- A Proven Track Record of Success: FactSage is a globally trusted tool utilized by over 800 corporations, universities, and research institutes across diverse sectors, including steelmaking, non-ferrous metals, precious metals, cement, ceramics, refractories, electric power, corrosion/protection, and waste management (as of 2016).

Over 20 Years of Dedicated Technical Support
We have been the official distributor of FactSage in Japan since 2001. Drawing upon our extensive, long-term experience, we share valuable insights and best practices for maximizing FactSage's capabilities through robust technical support, introductory training, regular seminars, user meetings, and complimentary hands-on workshops.
Through FactSage, we are fully committed to helping you analyze and predict phenomena using the laws of thermodynamics, reduce chemical experimentation costs, and achieve unparalleled efficiency in your research and development.

Link to the developer
- GTT-Technologies
Kaiserstrasse 103
52134 Herzogenrath
GERMANY
Web: - Thermfact Ltd.
447 Berwick
Mount Royal, Quebec
H3R IZ8, CANADA
Web: https://www.factsage.com/