Unfortunately, PowerPoint will only let you use a custom page size no larger than 56" inches. In order to workaround this limitation, we'll need you to set up your file to a smaller proportionate scale. The page size of your PowerPoint document must be the same aspect ratio as your final output size. Your file's page size need not be the same as the final output size, but must be the same aspect ratio. If, for example, you are going to order a 36x72 inch poster, your PowerPoint page size can be set to 24x48 or any other proportionate page size. You can use the chart to the right to help you work around the 56" limit.

To properly setup your PowerPoint page size in a new, blank file:
(If you have already designed your poster, skip to the next tutorial below.)

1. Open a new blank presentation in PowerPoint
2. Go to File>Page Setup
3. A dialog box will appear similar to the one on the right.
   Enter the width and height of the page. The slide orientation (portrait or landscape) will automatically adjust based on the page sizes entered.
4. Click OK
5. If the rulers are turned on (View>Ruler), you will be able to see that the slide is now the size entered.

Changing your page size with existing content on the slide is not a one step process. If you already have items on your PowerPoint slide and then change the page size, some items may become squashed and stretched. To properly setup your PowerPoint page size in a file with existing content:

1. Open your existing PowerPoint slide.
2. Select everything on your slide by pressing Ctrl + A.
3. Cut everything from your slide by pressing Ctrl + X.
4. Go to File>Page Setup
5. A dialog box will appear similar to the one on the right.
   Enter the width and height of the page. The slide orientation (portrait or landscape) will automatically adjust based on the page sizes entered.
6. Click OK
7. If the rulers are turned on (View>Ruler), you will be able to see that the slide is now the size entered.
8. Paste all of the items back on the slide by pressing Ctrl + V.
9. At this point, you will most likely have a lot of extra space on your slide, or have a lot of your content hanging off of the slide boundaries. Be sure to rearrage your content so that everything is displayed nicely on your new resized slide.