When I first started out in the tallit business, grappling with all the different sizes left me dazed and confused: Size 18, Size 24, Size 36, Size 45, etc., all the up to Size 90. These sizes are used throughout the industry and should actually be easier for English speakers, because they are based on inches.
Allow me to explain: the width of a tallit (i.e. from side to side while worn) varies relatively little, generally ranging from 72 to 80 inches. The key number is the height, because that indicates how far down the shoulders the tallit will hang.
The narrow tallit sizes, 18 and 24 are essentially like wide scarves. They do not cover the back, but only hang around the neck and in front. These are fairly common among Reform Jews, although full-size tallits seem to be making a comeback. For the not-so-tall bar mitzvah boy (under 5 feet) we also have customized tallits so that the tzitzit won’t drag on the floor.
Bar Mitzvah Tallit
A bar mitzvah boy will often choose a Size 45, Size 50 or Size 55, depending on his height (and how fast he’s growing!). This size might also be right for a short adult or a man of average height who wants a tallit that will just cover his upper back.
Traditional Tallit Sizing
For a full-length tallit, most men will choose a Size 55, Size 60 or Size 70, while tall men will go with a Size 80 or even a Size 90. Tallit size tables generally list sizes that will hang down to the back of the wearers knees. If you want a full-length tallit that’s a bit shorter and more manageable, go down one size.