If you are on low space on your hard disk, you can find out the uncompressed sizes of the files inside a zip archive, without unzipping it.
This is the command you need:
$ unzip -l ZipArchive.zip
The -l argument is for listing, the command does not extract the archive.
You will get a listiong of every file from the zip along with its uncompressed size (in bytes) and the total size on the final size (in bytes).