Model downloads are available in two versions:

  • The User Version allows opening, editing, and running scenarios. In addition to the model’s executable, running microWELT requires the installation of the Modgen Prerequisites package, which is freely available here
  • The Developer Version includes the Modgen Code and allows modifying and further developing the model itself. Customizing microWELT requires Microsoft Visual Studio (pro version, or the free Community Edition), as well as the installation of the Modgen Developers Package which is freely available here.

Model downloads include the parameters and base scenarios for four countries (Austria, Spain, UK, Finland).

The download of the User Version includes both a 32-bit and a 64-bit version:

  • microWELT.exe (32 bit) This version allows the editing of all parameter tables and - after running a scenario - makes all output tables accessible within the user interface. The downside of this version is that it only allows simulations requiring less than 4GB of RAM. Required RAM for microWELT depends on the simulation horizon, the number of parallel replicates run simultaneously, the selected sample size, and the scope of selected table output. For a simulation of a single replicate until 2060 selecting all available tables, this limit lies at a starting population size of around 150.000 persons. We recommend this version for training and testing; for most training purposes, a single model run with 50.000 persons will be sufficient.
  • microWELT64.exe (64 bit) This version removes the 4G RAM limitation; the maximum RAM is limited by the available RAM on the PC. For the analysis presented at, we typically run 12 replicates with a population size of 167.000 persons each. Unlike the 32 bit version, the display of parameters and output tables is not supported in this version. In order to use the 62-bit version, first, a scenario has to be prepared and saved using the 32bit version. The same applies for displaying the simulation results after running a scenario.