CAD tip # 9528:

The process differs in older (with standalone "hub") and newer versions of Fusion360.

In newer versions (integrated "Data Panel") just use the panel to Upload the source CAD file into your project, open the converted model in the Fusion editor and use File > Export to export it to the desired target format.

Or you can Upload from the web hub and then use extended export options available in the web hub (A360 Team), under the toolbox icon:

In older versions, conversions can be also executed directly from the Fusion 360 "hub" environment (without launching the 3D editor). Load the input file with the "Import" function. If you load an assembly (e.g. IAM), the option "Import an assembly" handles also loading and conversion of all individual parts of the 3D assembly model:

Newer versions of A360 can export only F3D (Fusion360) models into these formats:

You can also export from the viewer:

Overview of supported formats in Fusion360 (as of 7/2019):

In this way - without installing any CAD application - you can use Fusion 360 to convert CAD files e.g. from STL to DWG, from IPT to STL, from STEP to IGES, etc.

An overview of conversion options for CAD formats in Fusion 360 can be also found on the page format conversions.