This photograph shows all the canvas sizes that I use laid on top of each other, next to a piece of A4 paper, to give you a better ides of what the sizes are.
I mainly use rectangle shaped canvases, especially for the larger pieces, but I do have some square sizes available too.
Largest Rectangle = Xtra Large
£300 = 20″x 24″ (500mmx600mm)
2nd Largest Rectangle =Large
£180 = 16″x 20″ (406mmx508mm)
3rd Largest Rectangle/Largest Square = Medium
£150 = 12″x 16″ (305mmx406mm) rectangle
£150 = 12″x12″ (305mmx305mm) square
3rd Smallest Square/2nd Smallest Rectangle = Small/Medium
£75 = 8″x 10″ (203mmx254mm)
£75 = 8″x 8″ (203x203mm)
2nd Smallest Square/Smallest Rectangle/Small
£55 = 5″x 7″ (127mmx178mm)
£55 = 6″x 6″ (150mmx150mm)
£35 = 3″x 3″ (70mmx70mm)