Most listings are 8.5 x 11 inches (letter). A few items use slightly different measurements (for example, 8.5 x 11.75 or 11 x 9.625) and some descriptions use the 8 1/2" x 11" notation.
Many items list perforated pages or a perforated top edge for neat tear-out. Several product notes explicitly call out perforated sheets to make removing pages easy and tidy.
Both: some legal pads are offered in multipacks (one example lists a pack of 12), while many notebooks and pads are sold individually (package quantity 1).
Several pads and notebooks are 3-hole punched, making them suitable for standard three-ring binders. Some items also note that pages measure 8 1/2" x 11" when torn out for binder use.
Most listings reference white pages. Several items also note layout details such as a left-side margin, a title space on each page, and perforated sheets or a perforated top edge for easy tear-out.