Canvas Size for 4Rs

[cs_sim]

Hi,

It seems that digital photos always get cropped by the developing studio unless we request for the original digital prints. Would like to find out if anyone knows the canvas dimensions so that I can scale the photos down and reduce the amt of cropping required. Thanks!!!

 

[Squid]

3R = 3.5" x 5" (1,050 pixel x 1,500pixel)
4R = 4" x 6" (1,200 pixel x 1,800 pixel)
5R = 5" x 7" (1,500 pixel x 2,100 pixel)
6R = 6" x 8" (1,800 pixel x 2,400 pixel)
8R = 8" x 10" (2,400 pixel x 3,000 pixel)
S8R = 8" x 12" (2,400 pixel x 3,600 pixel)
10R = 10" x 12" (3,000 pixel x 3,600 pixel)
S10R = 10" x 15" (3,000 pixel x 4,500 pixel)

The above based on 1 inch : 300 pixels ratio