Size of each slide in a presentation

Have you tried the solution of Publishing each slide separately? Check the "How can I determine the size of individual slides in a PowerPoint slide deck?" answer

I'll copy the solution here, to not lose if they change anything:

1. File, Save & Send, Publish Slides, Publish Slides (button)

2. Select All - I recommend using Select All the first time so you can see the size of all your slides. Choose destination Windows folder. Publish

3. Review sizes and you can launch each individual-slide powerpoint file to see which one it is and whether you can reduce the size. After you have made ammendments you can individually choose which slides to Publish and see what effect your edits have made.

Excellent advice.  In case the PPT options are hard to read in the screen shots (and because they seem to be in (?) German, here are the steps:

• Make sure you've saved the presentation
• From the ribbon, choose File | Save & Send
• Click Publish Slides on the list of options given
• Click Publish Slides in the pane on the right

The rest of the steps should be simple to follow; choose the slides to export or select all, browse to the folder where you want the files saved and so on.

The saved slides will have the same filename as your original presentation, with 001, 002 added to the end.