I found the following Table online in this document (page 11): www.ivoa.net/documents/HiPS/20170406/PR-HIPS-1.0-20170406.pdf
First item is the Norder, second is the number of files (or tiles), third item is the angular size of each tile, fourth item is the angular size of each pixel in each tile.
So for example, if you are wishing to use the HiPS for framing, this tells you that Norder5 provides you with 12.88 arc seconds per pixel, which each tile being 1.832 degrees across.
Norder7 has each tile 27.48 arc minutes across, with a pixel size of 3.221 arc seconds.

FYI, Norder8 would be around 78GB in size, with a pixel size of 1.61 arc seconds (it appears to halve as you raise the HiPS order by 1)

0 12 58.63° 6.871'
1 48 29.32° 3.435'
2 192 14.66° 1.718'
3 768 7.329° 51.53”
4 3072 3.665° 25.77”
5 12288 1.832° 12.88”
6 49152 54.97' 6.442”
7 196608 27.48' 3.221”

Read More...