User:Zyxw/upright

The available values for thumbnail size in Special:Preferences (on the Appearance tab) are 120px, 150px, 180px, 200px, 220px (default), 250px, 300px, and 400px. As explained at,  will "adjust a thumbnail's size to Factor times the default thumbnail size, rounding the result to the nearest multiple of 10". That math can be done on Wikipedia via, which is how the following chart was generated.

Actual effects
The first column of the following table shows a frameless image at the user's current thumbnail size setting (220px for users who have not changed it or are not logged in). The second column shows the same frameless image with  or   added.

To see the actual effect at other thumbnail sizes, change the setting in Special:Preferences (on the Appearance tab), come back to this page, and either refresh it or click . View the HTML source via the web browser to confirm the actual sizes in the image tags.

Note: As shown in the first three rows,,  , and   all have the same effect.

Simulated effects
This first column of the following table shows an image at each of the thumbnail size settings available in Special:Preferences (400px was not included due to its effect on the table and page width). The second column shows simulated examples of how  would change each of those thumbnail sizes (the math used is shown in the heading above each adjusted image).