Conversion between zip and tar.gz files represents repacking files from a ZIP archive to a TAR.GZ archive format. Some programs may offer it directly, with others you will need to first decompress the .zip file and then pack the data again to a .tar.gz file.
Convert WinZIP Compressed ZIP archive to Old version Gzip compressed TAR Archive.
We have found one software suitable in our database for this conversion.
Apple macOS / Mac OS X software - convert zip to tar.gz on OS X
A program for creating Mac OS X disk images
Convert from zip file format
The table with program actions contains information about what each program is capable of doing with their files. This may be a good pointer for further searches for certain file conversions and help you find the converter you are looking for if our search result is insufficient for you. However, it is far from perfect and may sometimes show results which are not really usable because of the nature of the software handles the files. So a conversion that appears as possible, just because of matched actions, may in fact not be possible.