size conversion:
imperial ➡️ metric

inches | centimeters
8” x 10” | 20.32 x 25.4
11” x 14” | 27.94 x 35.56
12” x 18” | 30.48 x 45.72
16” x 24” | 40.64 x 60.96
18” x 24” | 45.72 x 60.96
30” x 36” | 76.2 x 91.44

for stretching: please select (add 3+ inches for canvases that you would like to stretch) in addition to the canvas print that you’d like
more sizing faq here