Cloud storage almost full with only 2967 photos

[default2osaypboypvy]

I have 100GB of Cloud Storage that contains only 2967 photos. I see a warning that my storage is almost full. Apparently the 2967 photos is taking up 96.99GB, this just isn't possible. Any suggestions on how to correct this would be greatly appreciated. 

[Rikk Flohr: Photography · Accepted solution]

Depending upon the camera and the file type 30 MB/image sounds about average. You don't say what file type or camera these files result from but that has a bearing...

Convert one 30 MB raw to a Tiff and it becomes 250 MB pretty quickly with an extra layer or two.